Suzanne Pleshette was cast after she appeared by accident on The Tonight Show Starring Johnny Carson (1962) seated next to Bob Newhart. Producers thought she and Bob clicked together and asked her to read for the show.

Bill Quinn, the actor who played the recurring role of the mailman for Bob Hartley's office building, was Newhart's father-in-law in real life.

When Bob Newhart read the premise for the proposed series, he insisted on two changes. First, he insisted that his character be changed from a psychiatrist to a psychologist so he wouldn't make fun of the seriously mentally ill, and he insisted that his character have no children as to avoid the standard scenario of a goofy father.

Bob Newhart was drunk during the scene in the third season opener where he slams closed the 'group in session' sign.

Even though Bob Newhart didn't want there to be children turning his show into a family sitcom, Emily Hartley did announce that she was pregnant during a show that turned out to be one of Bob's nightmares.

Actor Peter Bonerz who played Jerry the dentist learned how to direct on the set of this show and went on to become an award-winning director of other comedy series.

The characters Bob Hartley and Carol Kester-Bondurant appeared outside The Bob Newhart Show (1972) in the 1994 episode of Murphy Brown (1988) when Carol became Murphy's 66th secretary. Unlike all of Murphy's other secretaries, Carol (Marcia Wallace) is a great secretary. Unfortunately (for Murphy), Bob Newhart (as Bob Hartley) shows up at the end of the show to convinces her to come back to work for him.

The office building where Bob's office is located, according to the outside shots on the show, was at that time the Bay Federal Bank Building on Michigan Avenue.

When the scripts were first written for the show, writers would write the line "Bob reacts" just like they would for other comic actors. After a while, the writers stopped doing that because Bob basically had the same reaction to every bit. There was no need to write it.

Over the course of the series, the phrase, "Hi, Bob" was said 256 times. Howard Borden (Bill Daily) said it a total of 118 times. Dr. Jerry Robinson (Peter Bonerz) logged 43. Carol Kester (Marcia Wallace): 36 times and Emily Hartley (Suzanne Pleshette): 17 times. Minor characters or guest stars said it 43 times, and Bob Hartley (Bob Newhart) even said it once himself.

According to Bob Newhart, he always had his lines written on cards that were hidden around the set because he could not remember them.

It was later revealed that Jerry was adopted. Jerry did eventually find his mother, but his father, an American plumber working in England, was killed in an air raid during World War II

Bob Newhart and Peter Bonerz & Suzanne Pleshette are the only cast members to appear in all 142 episodes of the show.

A popular drinking game was invented by college students during the run of the show. Whenever someone on the show says, "Bob," each player had to take a drink. If someone said "Hi, Bob," you had to guzzle your drink.

Prior to her regular role as Miss Larson, 'Penny Marshall' appeared in the series' first episode as The Stewardess ("Fly the Unfriendly Skies", 16 September 1972).

Over the course of several shows ,Bob's office number keeps changing. In some shows it's 715 and others it's 751. In a season 2 show ,the door reads 715 outside the office. Later ,when he and a patient leave ,it's back to 751 again.

The exterior office building shots, where Bob's office was supposed to be located, were of the Uptown Federal Savings Building at 430 North Michigan Avenue near the Wrigley Building. The Uptown Federal Savings sign on the building can clearly be seen in many of the shots.

Bob and Emily lived in apartment #523.

Over the course of the show they make about 5 separate references to Bob being in the Korean war. Problem is 2 of the references were of Bob being in the Air Force and 3 were of Bob being in the Army.

Bob's office was on the seventh floor, suite #751.

The zip code of Robert Hartley's apartment building address in Chicago, IL was 60611. The actual building used for exterior shots of Bob's apartment is on North Sheridan Road, and bears zip code 60660. It abuts Lake Michigan on the East. Ironically, the office building used does, in reality, bear zip code 60611.

In season 3, it's said that Bob is 45 years old. A few episodes later, Bob says his mother was 56, which would have made her 11 years old when she had him.

In the episode, "The Great Rent Strike" we learn that Bob and Emily live in apartment #523.