In the first season Donna Martin's mother was named 'Nancy Martin' and played by actress Jordana Capra when she was reintroduced in season 2 she was named 'Felice Martin' and was now played by actress Katherine Cannon.
Kristin Dattilo was up for the role of Brenda Walsh, but turned it down. She would later guest star as Melissa Coolidge in an episode of the first season. Beverly Hills, 90210: One Man and a Baby (1991).
Steve has shaving cream on his ears, but when the camera goes to a different angle the shaving cream is gone, and again when it goes back to the other camera angle, the shaving cream appears again.
In an episode following the death of Noah's father, Noah is showing Valerie his parents' home. While touring the house, Valerie enters the kitchen wearing a different pair of shoes than in the previous room.