The role of Monica was originally conceived as the oldest of the friends, but was changed after Courteney Cox Arquette was cast. Ironically, Courteney Cox is the second oldest member of the Friends cast.

When they are choosing a name for Ross and Rachel's baby who is later named Emma, Monica said that she would name her son Daniel. However, in the last episode, she names her son Jack after her father. Also, when Monica and Chandler were having sex when they were babysitting Emma, Joey said he wouldn't tell Rachel if they named their first son Joey.

Monica lost her weight because she overheard Chandler making fun of her during the first Thanksgiving he spent with the Geller Family. Monica also became a chef because Chandler liked her macaroni and cheese and jokingly told her she should be a chef.

Monica's apartment was one of the main focal points of the series. Many critics of the show began to question how Monica could ever afford the apartment on a chef's salary, so the writers of Friends came up with the explanation that she illegally sublet the apartment from her grandmother, who had moved to Florida. Also, in the final episode, Chandler remarks to his newborn child that "thanks to rent control, it was a friggin' steal."

Monica is the only of the female 'friends' that has never been pregnant: Rachel was pregnant with Emma, and Phoebe with Frank Jr.'s triplets. Near the end of the series, it was discovered that Monica's womb was virtually infertile, presenting an extremely "inhospitable environment."

Actress Jami Gertz was offered and declined the role of Monica before Friends went into production.

Monica is the only female Friend to have been seen naked by all of the other Friends.

Despite Monica's skill in Foosball and football (see Competitiveness above), she is remarkably uninformed about professional sports. When reading the newspaper to a man in a coma, she condenses the sports section into "teams played sports." After Monica asks what she should wear to a New York Knicks game, Chandler suggests "a T-shirt that says, 'I don’t belong here.'"

Despite her petite size she is frequently referred to as being "freakishly strong" by the others.

Monica had at least two jars that she had to put a dollar in: a "Richard jar" for whenever she mentioned her old boyfriend Richard Burke once she started going out with Chandler, and a jar at her restaurant that she had to contribute to whenever she yelled at her staff.

Monica's viewpoint on smoking is not consistent. Although she gets furious at Chandler when he smokes cigarettes, she didn't seem to mind Richard smoking cigars when they went out and even admitted that she likes the smell. Also after they broke up and Monica was still missing him, she found one of Richard's old cigars and started smoking on it. On her 30th birthday, she gets drunk and admits to smoking a cigarette herself once.

Early in the series, the writers were going to have a relationship between Monica and Joey, rather than Chandler. This can be picked up on the fact that she had a crush on Joey when he first moves in and is even sneaked in when it's revealed that Monica was looking for Joey on the night of Ross' wedding, not Chandler.

Monica is fairly open when it comes to videotaping sex and porn. She makes tapes with Richard and Pete, and started to make one with Chandler before they were interrupted by Joey. After they were married, she bought Chandler porn for Valentine's Day and, after surprising Chandler in Tulsa, even tries to buy shark porn in "The One with the Sharks" after mistakenly thinking that he is turned on by sharks. However in the episode "The One Where Ross Meets Elizabeth's Dad," she expresses visible discomfort at the fact Chandler has porn on his computer.

At a college party Monica's brother Ross once kissed her while she was asleep, believing her to be Rachel "under a pile of coats." When this is discovered Ross is horrified and asks "YOU were my first kiss with Rachel?!" to which Monica responds "YOU were my first kiss EVER!", to which Chandler remarks "What am I marrying into?!?"

Monica is allergic to cat hair despite having a cat named "Fluffy Meowington" once. This can be explained by having her allergies developing after her (and presumably Ross') cat's death.

Monica says the first lines in the series.