When the show was broadcast in the UK, many viewers wrote in to chide Charles Shaughnessy over his "fake" English accent, and suggested he practice with co-star Daniel Davis on how to do a proper English accent. The cast found this quite amusing, as Shaughnessy is a native Englishman born in London, while Davis is an American born in Arkansas.
During the show's fifth season run, both Lauren Lane and Rachel Chagall became pregnant twice on the show. But unlike other sitcoms that hid their pregnant actresses behind props or had them sitting, producers of this show made no attempt to hide or explain the growing bellies, except for one episode where C.C. makes a reference to Elaine on Seinfeld (1989) being hidden by props when she became pregnant and she is jokingly hiding herself with props.
"The Nanny" was more of a family affair than most shows since Fran Drescher's company produced the show and hired many friends and relatives to be regulars, guest stars and production staff. The show was also on six years without a major change in casting which was due in part to the congenial working conditions on the set of the show.
Throughout the series, viewers see that Maxwell has a brother (Nigel) and a sister (Jocelyn) but they are never shown in the same episodes. Also, in episodes where Nigel makes an appearance Jocelyn is never mentioned, and when Jocelyn is in an episode Nigel is never mentioned.
Yetta's background changes throughout the show more than anything else in the series. She had her sweet sixteen on Ellis Island, she came to America with an arranged marriage, she got married in the old country, she fled Poland for her first wedding anniversary, she got married because she got knocked up by the seltzer man, she was on the Titanic, she was at Pearl Harbor; her story constantly changes. However, there have been many subtle, strong, and in some cases, obvious hints at Yetta's senility, so the many contradictory stories about her past would not necessarily all be true.
It's mentioned throughout the series that Maxwell passed on the musical "Cats", which has been noted as his biggest career mistake. In several episodes it's also mentioned that he passed on "Hair" and "Tommy" as well.
The producers planned to make the main character of Fran an Italian-American, but Drescher wanted the character to remain Jewish. The character of Val Toriello, however, is Italian-American, although Rachel Chagall is actually Jewish.