Larry (William Sanderson), Darryl (Tony Papenfuss) and Darryl (John Voldstad) were supposed to be one-time characters, but the studio audience's reaction to their introduction was so spontaneous the producers decided to make them regular characters..
It was Bob Newhart's idea to begin using film from season two onward in order to give the show a more realistic look.
The opening credits are outtakes of On Golden Pond (1981). If you look closely, you can see Henry Fonda and Katharine Hepburn in the car. William Lanteau, who was the recurring role of Chester in the series, was also in On Golden Pond (1981).
Vermont residents complained that the opening scenes are of New Hampshire, not Vermont.
Mary Frann (Joanna Loudon) visited several Vermont inns to do research and brought back the Pfaltzgraff dishes that are seen as props in the Stratford Inn.
Jerry Van Dyke was the first choice to play George Utley, but his audition for the role was unsuccessful.
Darryl and Darryl were originally named Larry. They altered their given names to avoid confusion both at home and at obedience school.
At the end of each episode, the voice of the kitten meowing in the "MTM" logo is that of Bob Newhart.
During the show's entire eight year run, the name of the town or community where The Vermont Inn was located was never mentioned.
Larry always wears a quarter in his ear. William Sanderson also used this prop in Coal Miner's Daughter (1980).
Julia Duffy was pregnant during several episodes of the show and had to hide her condition by wearing baggy clothes and standing behind furniture.
Darryl (unclear whether it's one or both) doesn't talk because when he was seven years old, he sat on a porcupine and "he ain't talked since."
The role of Larry was written for Tracey Walter. He auditioned, but William Sanderson was eventually cast.
Over the course of the series, how long the Loudons had been married kept changing. In an early episode in 1982 they'd been married 16 years; in a 1984 show it was said to be 12 years; when the Loudons are going to renew their vows in 1986, it was said to be 15 years.
In a later-season episode, Chester, the town's absent-minded mayor barrels into the Stratford end shouting "Thomas Hill Bridge is out!" Thomas Hill played Jim Dixon, Chester's buffoonish friend.
The characters Larry, Darryl and Darryl, who often waxed philosophical, probably got their names from the main character of the book "The Razor's Edge", by W. Somerset Maugham, Larry Darrell, who traveled the world looking for the meaning of life.