Many of the gags seen on the show were on-the-spot improvisations by Robin Williams, and later by Williams and Jonathan Winters. If you pay attention to Pam Dawber, you can often see her having difficulty not laughing at the ad libs.
When Conrad Janis and Elizabeth Kerr temporarily left the show, their absences were explained by having Fred fulfilling his dream of becoming a conductor and going on the road and Cora joining him there.
Orkans evolved from chickens.
Mork and Mindy's downstairs neighbor, Mr. Bickley, wrote greeting cards for a living.
As of 2004 Mork and Mindy's house is the most popular landmark in Boulder, Colorado.
The house used for the exterior shots of Mindy's home is at 1619 Pine St near downtown Boulder. Mindy's father's music store was actually a bookstore on Boulder's Pearl Street Mall.
Producer Garry Marshall said he came up with the basic concept of the show during a phone call with an ABC executive. He said he set the show in the college town of Boulder because he had a friend with a child attending Colorado University.
Jonathan Winters' first appearance on the show was as Dave McConnell (one of Mindy's relatives) in "Mork and the Family Reunion". Winters went on to join the cast full-time as Mearth in the following season.
Mork's furry alien pet, Bebo, was credited as himself.
During casting, when asked to take a seat, Robin Willams sat in the chair upside down. Producer Gary Marshal selected him because "He was the only alien to audition."
Pam Dawber did not attend her audition for the part of Mindy McConnell in person. She made an audition videotape of her performance as Mindy, spliced together with scenes from 'Robin Williams'' earlier appearance as Mork on "Happy Days" (1974). In the audition tape, Dawber simply reacted to everything that Williams said in his "Happy Days" appearance. She got the part because the producers felt she was the perfect "straight-person" for Williams' wacky alien.