When Rocky is training for the fight, he is sparring with a smaller quicker fighter. The sparring partner is played by real life Champion Roberto Durán.

It took Sylvester Stallone and editors Danford B. Greene and Stanford C. Allen over eight months to edit the climatic fight scene so as to meet Stallone's approval.

In one version of the screenplay, there is a flashback scene that shows Rocky first meeting Mickey and we learn Rocky's real first name: Robert.

Sylvester Stallone himself wrote the paperback novelization for this movie. The novel is mostly in first person, from Rocky's point of view, written in the same choppy English in which Rocky speaks. Scenes in which Rocky is not present (such as Apollo Creed consulting his associates, or Paulie alone with Adrian) are in standard third-person, in proper English.

800 local schoolchildren were used as extras for the scene depicting Rocky's run through Philadelphia.

After the bell rings, signaling the end of the second round, Sylvester Stallone and Carl Weathers are seen pushing, shoving, taunting, and ultimately being pulled apart by their respective cornermen. They continue to taunt each other before returning to their corners. Stallone revealed later they were actually angry with each other and were not acting at that point, several blows that were supposed to miss him landed and the carefully choreographed fight, which they spent months meticulously planning out, went off-track during that scene, but he liked the reaction the scene produced. He decided to leave their momentary breaking of character in and the viewing audience never realized the two actors were in reality quite livid with each other.

During his preparation for the film, Sylvester Stallone was bench-pressing 220 pounds, when the weight fell and tore his right pectoral muscle. This was shortly before the fight scene was to be filmed, and ultimately, the scene was shot with Stallone still badly injured.

Analysis by Philadelphia locals tracked the route Rocky took through the city during his training run when all the children ended up running with him. If he took this actual route from his South Philly house to the top of the Art Museum steps he would've run approximately 30.2 miles in one day - 4 miles more than a marathon.

Originally, Adrian was supposed to be at the big fight. However, because Talia Shire was working on another movie at the time, the storyline was changed to having her stay home and watch the fight on television. The scenes of her watching the boxing match on television were shot, and then edited into the movie several months after filming once the fight scenes had finished.

Sylvester Stallone began working on the Rocky III (1982) script immediately after completing Rocky II, with the intention of the series being a trilogy. Originally, he had no plans to make a fourth film.

During the main fight, Apollo Creed is wearing the exact same red and white-trimmed shorts as Rocky was wearing on the overhead banner with his picture during the first fight in Rocky (1976).

Sylvester Stallone's infant son Seargeoh Stallone played the newborn Robert Balboa, Jr. The role would later be played by his elder brother Sage Stallone in Rocky V (1990).

On Friday Night with Jonathan Ross (2001), Sylvester Stallone was asked to give each Rocky a score out of 10. He gave this one a 7 1/2.

In the first film, Rocky becomes angry when Gazzo's driver suggests he take Adrian to the zoo because "retards like the zoo", insisting she is just shy. In this film, Rocky proposes to Adrian at the zoo.

As he had done with the original, Sylvester Stallone incorporated biographical elements from his own life into Rocky's story for this film. In particular, Stallone used as a central plot point the concept that yesterday's heroes are quickly forgotten. In the film, this manifests itself in terms of people quickly forgetting about Rocky's exploits in the title fight. In reality, Stallone experienced a similar sense of being quickly forgotten after his two post-Rocky (1976) movies, Paradise Alley (1978) (Stallone's directorial debut) and F.I.S.T. (1978), both of which underperformed at the box office.

In the scene where Rocky is filming a commercial for Beast cologne, one of the chairs in the background reads Joe Spinell, the actor who played loan shark Tony Gazzo in Rocky (1976) and this film.

In the first draft of the script, the fight took place at the Roman Colosseum.

During the commercial filming scene, the clapper-board reads "Director: John Pleshette", the real name of the actor playing the director. Also, Duke (Apollo's Trainer), the Agent and the Meat Foreman (played by Tony Burton, Leonard Gaines and Frank McRae respectively) are all referred to by their real Christian names in the script, while the Referee is introduced as Lou Fillipo, again the real-life name of the actor (who is also a professional fight referee).

Chuck Wepner, the real-life inspiration for Rocky (1976), was offered the part of a trainer named "Chink Weber". According to Wepner, he read for Sylvester Stallone but did very poorly. The character was deleted from the script. The name "Chink Weber" ended up being used for Sonny Landham's character in Stallone's movie Lock Up (1989).

The book that Rocky reads to Adrian is Edgar Rice Burroughs' "The Deputy Sheriff of Comanche County" which was originally published in 1940.

Butkus Stallone is wearing a shirt that says "Eagles" and the number 51. In 1976, when this film is set, no player on the Philadelphia Eagles wore number 51. In 1979, when this film was released, linebacker Reggie Wilkes wore #51.

For the first fight with Apollo, Rocky was paid $150,000. He tells Gazzo that, after taxes, he has cleared $37,000 .

The film takes place in 1976.

During the ambulance drive to the hospital during the opening credits, the movie poster from Paradise Alley (1978) also written, directed by and starring Sylvester Stallone can be seen on the back of a bus.

Apollo Creed does not smile once throughout the whole movie.

This is the third of four Stallone films that actor Frank McRae appeared in. He was also in F.I.S.T. (1978) and Paradise Alley (1978). And Lock up

Actor Shaka Cumbuka, who is credited as "Cornerman" for this film, actually had a name in the Rocky: Legends video game. He was called Randy Tate, and was also a playable character.

Before the fight begins, one of the announcers states that Apollo wants to draw "First Blood", which is the name of Sylvester Stallone's original Rambo movie in 1982.

The hospital Rocky and Apollo were taken to at the beginning is Pennsylvania Hospital. The nurse who asks Rocky for an autograph is wearing a button which reads "I'm proud to work at the nation's first hospital, celebrating 225 years in 1976." Pennsylvania Hospital was founded in 1751 and is located at 800 Spruce Street in Philadelphia.

Film debut of Paul McCrane.

During the scene with Rocky and Apollo talking to the media one reporter asks Rocky what he might do with his money and replies by telling her he's going to buy Pauley a snow cone machine, buy the Church a statue and buy his unborn child some muppet toys and mentions Kermit the Frog. Sylvester Stallone had been a guest on the Muppet Show earlier that same year in 1979.

Part of a cycle of ring fighter movies, mostly boxing, some wrestling, initiated by the box-office and critical success of the Academy Award Best Picture winning boxing movie Rocky (1976). The films include Rocky II (1979), Rocky III (1982), Rocky IV (1985), Tough Enough (1983), Title Shot (1979), Raging Bull (1980), The Champ (1979), Matilda (1978), The Main Event (1979), The Prize Fighter (1979), The Greatest (1977), Body and Soul (1981), Paradise Alley (1978), ...All the Marbles (1981), The One and Only (1978), Every Which Way but Loose (1978) and Any Which Way You Can (1980).

The only Rocky movie where Adrian and Paulie were not present at the fight.

Curiously, some genetically southpaw left-handed boxers actually fight right-handed, sometimes due to a result of "fitting in" during training, as right-handed is the majority. And equally, some genetically right-handed boxers play left-handed to give them an edge in a fight against right-handers. Although, when 2 southpaws fight, its just a flipped version of 2 right-handers. Robert "Rocky" Balboa could actually be a right-handed boxer that fights southpaw, which could explain away the fact that he signs the autograph right-handed, although he fights left-handed.

At various times during this film, and other films in the Rocky-Creed film series, at times it's unclear as to if the characters are saying Rocky or Robby, Rock or Rob. This may just be a mis-hearing once the viewer learns that his real first name is Robert, but it actually also works within the scenes anyway as they may be talking to his boxing persona "Rocky", and/or to the real Rob, Robby/Robert when its a more serious scene.

At the end of the rematch, Rocky knocks Apollo down, and then falls to the canvas with him simultaneously after following through on the punch he lands. The announcers both mentioned the first to get up would be the winner, and if neither of them had gotten up, it would have been a draw and Apollo would have kept the title. While the latter is true, the Champion does retain the title if the decision is a draw, that would never have happened if it had been a real fight. Since Rocky slipped, fell, and knocked Apollo down, Rocky would have been declared the winner because he knocked Apollo down and stumbled to the canvas rather than being knocked down by Apollo. Even though he got up first, Rocky's falling to the canvas would have been ruled a slip, and Rocky would have won by knockout anyway.

In the hospital scenes, Adrian's room number is 669. The number 669 is considered as an "Angel Number." This sequence in the movie shows a lot of Christian crosses and instances where Rocky is sitting in the chapel.

According to the director of the original film, John G. Avildsen, in a 1980s newspaper interview, one of the main reasons he did not direct this sequel (besides preparing for his role as director for Saturday Night Fever (1977)) was that he didn't approve of the story. He was, however, fond of Stallone's original concepts for the two films which would have made the series a trilogy. The plots would have had Rocky be elected mayor of Philadelphia on the Reform Ticket, only to be scandalized when Paulie is caught stealing from the treasury. Rocky takes the blame, is kicked out of office, and ends up penniless just as he was at the beginning of the series. Coincidentally, this is similar to a scenario that Stallone and Avildsen collaborated on for Rocky V (1990)

Rocky didn't really win the rematch as much as Apollo lost it. Apollo was way ahead on the scorecards, and would have easily won by decision. Apollo punched toe to toe with him, allowing Rocky to make close enough contact to knock him out. A similar situation happened in a real-life heavyweight fight. On June 18, 1941, Billy Conn was on his way to winning a decision against Joe Louis, the World Heavyweight Champion at the time. During the 13th round, he abandoned the "stick-and-move" tactics (jabbing and staying away) that helped him get and stay ahead, and tried to knock Louis out. Louis landed a right to Conn's jaw resulting in a win for the Champ by KO and thus, he retained the Heavyweight Title.

Actress Rutunya Alda, who played Dr Cooper, is the doctor that comes in and tells Rocky and Paulie that Rocky has a son, and Adrian has slipped into a coma. Rutunya Alda also played the wife of Burt Young, (who played Paulie) n the sequel to "The Amityville Horror" (1979) called, "Amityville II: The Possession." (1982.)