One on One - S1-E5
Continuity mistake: They say it's October, but it was November in the previous episode.
Perfect Mom - S1-E7
Continuity mistake: When Jackie walks out and Cindy walks in, she closes the door behind her. However, despite the door being closed, Brenda walks in. (00:36:05)
Perfect Mom - S1-E7
Continuity mistake: In this episode we are (at the fashion show) introduced to Donna's mother for The First Time. She is called on stage as Nancy Martin. In all further episodes she is known as Felice Martin.
Continuity mistake: In season 1 episode 12 while playing ouija board Brenda says she "doesn't know any dead people", but in this episode it's revealed that her aunt died 2 years ago from cancer.
Continuity mistake: In the beginning of the episode Brenda takes her mom's coat to drama class and is wearing a blue shirt and white biker shorts. That night the parents go to the beach club. The next morning before school they show Brenda holding the coat and again in the blue shirt and white shorts she wore the "day before."
Continuity mistake: Brenda goes to see a counselor about the robbery. She asks what to do about the nightmares. The counselor asks about her happiest moment. Brenda starts talking about her horse she had as a child. She starts out saying his name was Sebastian but by the end of her story she says his name is Sylvester.
Continuity mistake: In this episode, Steve breaks into the school to improve his school grades in order to get into USC, because that is where his Dad went. But when the gang does go to college at CU, Steve's father is an alumni of that college not USC.
Continuity mistake: This is the first episode in which Kelly celebrates a birthday, and it is in March. A few seasons later, Kelly has another birthday, but this is celebrated in one of the first episodes of the season and takes place when everyone has just returned from their summer excursions. This would put her birthday in September.
Continuity mistake: At the pre-prom party, the head in Kelly's glass of champagne disappears. No time has passed, so it hasn't gone flat. (00:25:45)
Continuity mistake: During the scene in the kitchen where Brenda is at the table and her parents are talking to her about Stuart and then ask her if she wants a piece of pie, her arms are out in front of her on the table at this point. A split second later (same sentence), a rear camera view now has her left arm up holding her chin. A split second later after that when she answers "no", the front camera view now has her arms on the table as they had been all long.
Twenty Years Ago Today - S4-E8
Continuity mistake: In the scene where Brandon is going back to Dylan's house to retrieve his parents' wedding anniversary gift, when he is in the car and when he jumps out hurrying to the house he has his sunglasses on, but in the next shot with a different camera angle, as Brandon continues to hurry to the house, he has no sunglasses on. (00:22:00)
Continuity mistake: During the scene where David, Donna, and Andrea are in the casino and Andrea puts one dollar in a slot machine and hits the $500 jackpot, she screams and David tells Donna to get some buckets so that they may put all the coins in them. At that exact moment, they are interrupted by a security guard who asks them for their id's and when he figures out they aren't 21, he asks them to hand over the buckets of coins. At this moment, David and Donna hand over at least one bucket of coins. However, between the time David told Donna to get the buckets and when the security guard questioned them, the gang did not (and had no time to) get to fill up any of the buckets full of coins.
Crunch Time - S4-E16
Continuity mistake: At the end of the episode, Steve and John Sears are behind the table and one of them is about to be voted out of the fraternity. Pay attention to the scene where fraternity president Mike Ryan is giving instructions to the other fraternity brothers on how to vote and behave during this process. At the exact scene where Mike Ryan says, 'Your absolute silence is required', in the background we see Steve and John Sears staring down each other in anger. A split second later just as Mike Ryan finishes that sentence, the camera shot now just shows Steve sitting straight forward, looking down at his lap slightly in a kind of sad, defeated state.
Vital Signs - S4-E30
Continuity mistake: Near the beginning of this episode Andrea is awakened at 3 A.M. by an alarm clock to take a pill to stop her preterm labor. Several times in the episode it is mentioned she must take the pill every 4 hours. Later the alarm goes off at 8 PM the same day and she says "time for the pill again that is not doing me any good". If the alarm went off at 3, 8pm doesn't fit the 4 hour timeframe.
Continuity mistake: When Jesse takes Dylan's shot glass, he grabs it at the bottom, but in the next shot, he's holding it near the rim. (00:28:55)
Continuity mistake: When Steve is talking to his dad after he finished his case in court, one shot Steve's suit jacket is buttoned up. In the next second it is opened and all the buttons are down. (00:32:40)
Hazardous to Your Health - S5-E18
Continuity mistake: When Jonesy transfers Dylan's money out of the Cayman Island account, he is seen holding his hands around his neck. In the next shot he has his left arm down by his side and his right hand balled into a fist in front of his face. (00:32:45)
Continuity mistake: When Colin and Kelly celebrate his selling some of his artwork, the head in his glass of champagne disappears and then reappears.
Continuity mistake: When they are watching Colin's car chase at television, Colin is wearing an orange shirt. But Colin was wearing a grey shirt before the car chase started, and he is also wearing a grey shirt when he is caught.
Continuity mistake: Taz (lead singer of group Donna and David are producing a music video for) recognizes Kelly from her 'Seventeen' magazine cover and mentions it was in spring (May) 1994; however that was still the gang's freshman year in college (Season 4) and Kelly did not do the Seventeen shoot until season 5, and the magazine cover was out in the spring of 1995.