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.
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.
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
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).
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.
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.
Bob and Emily lived in apartment #523.
Bob's office was on the seventh floor, suite #715.
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.
Even though Bob Newhart didn't want there to be children turning his show into a family sitcom, Emily Hartley did announced that she was pregnant during a show that turned out to be one of Bob's nightmares.
Bob Newhart and Peter Bonerz are the only cast members to appear in all 142 episodes of the show.