Character mistake: When the Brady kids are practicing for the talent show, instead of saying, "Come on, Pete," Marcia says, "Come on Chris," which is the actor playing Peter's real name (Christopher Knight). (00:14:30)
Visible crew/equipment: When Mike and Bobby drive up in the station wagon, just as Mike stops the car, on the left side of the screen we can see the edge of the house set. Instead of the usual wood fence in the yard, there appears to be a directors chair (provided to all cast members) in the dark background. (00:05:35)
Dear Libby - S1-E2
Visible crew/equipment: When Carol questions Greg, Jan, and Peter about the argument she heard, Greg tells her it was on TV, and as the three kids sit down the actor's two tapes marks are visible on the floor in front of Peter's feet. (00:10:00)
Career Fever - S4-E9
Plot hole: Peter thinks he has a fatal disease. The parents realise two pages stuck together and he went from page 95 to 98 mistakenly. However, Mike first read about the actual fatal disease info on page 97, and then Carol read about what Peter actually had on page 96 (poison ivy). If Peter read only 95 and 98, there would be no way of Peter to know his disease was fatal since that was printed on page 97.
Lights Out - S2-E20
Revealing mistake: When Peter is on stage at his school for the talent show, Cindy gets into the disappearing lady booth and Peter closes the curtain. He says the magic words, yanks open the curtain and Cindy has disappeared. Look at the top left side of the booth and you can see where the stage curtain is piled up on top of the booth. There is just enough room for Susan Olsen to get out of the booth and then get back in.
Snow White and the Seven Bradys - S5-E3
Continuity mistake: When Mike rides up on stage he points to the damsel in distress with his right arm extended, but in the closeup it's his left arm extended.
Deliberate mistake: When Bobby's at the treehouse the second time for his initiation into the club, there's a boy already up in the treehouse, and after Peter takes the birdcage from Bobby's hand, the next closeup of the boy in the treehouse is a flipped shot, note the wood boards. (00:08:25)
Deliberate mistake: During Peter's party, when the girls start to gather around Peter to try and convince him that he's not dull, there's a closeup of Peter that's a flipped shot. Additionally, when everyone runs out for the fire drill, Peter's striped tie is tied very differently - it goes from grey/gold at the top to burgundy at the top.
Confessions, Confessions - S2-E12
Visible crew/equipment: During dinner, when the freshly glued vase with the flowers springs a few leaks we can see the top of the kitchen set in some shots, particularly when Alice makes the joke about three coins for the fountain.
Continuity mistake: When Marcia is cheering in the backyard, her locket tucks itself into her shirt when she finishes.
Other mistake: Carol grabs a pot holder with her right hand and removes a small cake from the oven. The cake pan is obviously not hot. It starts to tip and Carol steadies it by placing her bare left hand on the underside of the pan.
Fright Night - S4-E6
Continuity mistake: Mr. Brady places the bust on the half-wall behind the couch. When Alice swings her purse at it, it shatters immediately, but when the lights are turned on, it looks like all of the pieces are in the middle of the floor between the couch and chair.
The Great Earring Caper - S4-E20
Continuity mistake: During the kids' ping pong game in the backyard, there is something white near Jan's feet that appears to be a spare ball. But in the very next shot, it's gone. (00:12:40)
Visible crew/equipment: In the episode where Alice sprains her ankle, Sam comes over and gives Alice some flowers. He leaves and Mike walks in, and the camera zooms into Alice and you can see two shadows of the boom mic, one on Mike's face and another over Alice. (00:14:00)
Character mistake: In the courtroom, Cindy and Bobby are repeating their fight over spilling ice cream and Cindy says "You spilled ice cream on my dress" but at the start of the episode when coming home from the store, Cindy is wearing pants, not a dress.
Confessions, Confessions - S2-E12
Continuity mistake: When the vase gets broken, it's easy to see that one large piece flies off the chest of drawers onto the floor. And when the boys look down at the broken vase from upstairs, three pieces are on top of the chest of drawers. But Greg - seen later trying to fix it - says something to the effect of "Good thing it only broke into three pieces." So what about the piece that flew off onto the floor? (00:02:00)
Is There a Doctor in the House? - S1-E13
Plot hole: Lots of factors here: The doctors end up with the opposite kids that they were supposed to have... Why didn't they simply switch in the first place rather than go through all the drama? Also, the male doctor admits Alice let him in and most likely Alice would have told him first door on the right (like she's given directions in other episodes) to locate Peter. And the biggest question of all is, what doctor would make a house call and not look for their patient rather than just ending up with someone else they were not called to see (remember, each parent called their own doctor to see their biological kid).
Suggested correction: The lady doctor goes to see Peter as Mrs. Brady directs her to Peter's room first. Alice likely knows Peter already has a doctor looking after him, as it can be assumed Carol told her, so she sends the male doctor to Jan's room likely explaining to him that Mike's new daughter is also sick and needs to be checked. As to why they didn't solve this doctor problem to begin with; simply they are still a new family and didn't yet think about this as this is the first time the kids are sick.
Alice's September Song - S2-E23
Revealing mistake: One of the times that Sam comes over to visit Mr. Brady, he comes in through the back sliding "glass" door. There is no glass in the door. You can tell this because when Sam closes the door, to do so, he puts his hand through the areas where glass would be.
Is There a Doctor in the House? - S1-E13
Audio problem: When Mike walks into the kitchen and sees the chart with the list of kids on it and what ailments they've had, he comments on one of the ailments, saying "None of the kids have had distemper." However, if you watch his mouth, he appears to have originally said "rabies."
Continuity mistake: In episode 5-8 the girls have their walls wallpapered from pink to a yellow pattern with a white background. In the next episode it is back to the pink walls. The following episode it is back to the new wallpaper.