Continuity mistake: At the picnic, Bulldog puts his hand on the shoulder of a little girl in a dark pink dress, just before the pinata bashing starts; the next shot shows the same little girl is standing on the other side of the pinata, next to a woman in a blue and white striped top.
Continuity mistake: Marty and Niles are getting off the elevator and Marty transfers his mail into his left hand just as he goes to open the door to Frasier's apartment. When the shot changes to show them coming into the apartment, the mail is in Marty's right hand - there is no way he could have transferred the mail again in such a short time.
Continuity mistake: Niles runs into the kitchen where he finds Frasier cleaning the oven. As Frasier stands up, one of the cuffs on his rubber gloves has been turned over, and the other hasn't. A couple of shots later they are both neatly folded over. As Frasier leaves the kitchen, they are back to the first position. At no time did he adjust them.
Continuity mistake: In the opening scene, Niles goes to pour sugar on his spoon and the top of the sugar dispenser comes off and disappears - it looks like it goes into his lap. We don't see the top again until after the teenager says, "Aren't you going to yell at them?" and suddenly it is in plain view, on the right of the table.
Continuity mistake: Frasier comes home to his apartment with a bottle of wine in a paper bag. He takes the bottle out and puts it on the table holding the bag in the other hand, but in the next shot we see the bag is already on the table and he is just placing the bottle down.
Continuity mistake: Marty, Frasier, Niles, and Daphne are in Frasier's apartment, talking about Marty moving in with Niles - M.'s beer can and remote are sitting on his little table. In one shot they are quite close together, but in the next the can has moved about six inches forward.
Audio problem: As Frasier walks into Niles' kitchen, Daphne is on the phone, talking. We hear a hoarse sound, like Frasier's voice, saying "Daph" or "Dad" but it makes no sense as she is on the phone talking to someone, and he is heading for the fridge. When she hangs up, she and Frasier start talking about her employment situation.
Continuity mistake: Eddie has been playing on Niles' couch, and the pillows are all over the place and there are a couple of other things on there as well. After Marty's chair arrives, Niles says to Frasier, "You have to take him back now," and suddenly the couch is all tidied up, with the pillows at the ends. A couple of shots go by and suddenly the couch is a mess again.
Character mistake: In the last minute of the show, Frasier and Niles set to leave the bar. Frasier puts money on the bar to pay and the wife comes over and talks to them. Frasier moves the remaining money to his other hand. You can see his hands slightly twitching, and he accidentally drops the money on the floor, but acts like he is putting it in his pocket instead of picking it up, and leaves.