Continuity mistake: In their first night at the new house the Beardsley's lose power completely. When the doctor arrives (Tom Bosley) he rings the electric doorbell.
Suggested correction: We have had the power go out at our house before and the doorbell still worked.
Factual error: When Mike is leaving to join the Marines he is in full uniform. Uniforms are not issued to new recruits until after they are processed in. They arrive at Camp Pendleton in civvies.
Plot hole: In the scene after Frank talks to Helen in the dispensary about Louise, Frank decides to look Helen up in the phone book and ask her to dinner. Considering Helen had only recently moved to San Francisco, it's amazing how quickly she became listed.
Continuity mistake: When Helen and Frank are out on their first date, Helen loses her slip in the bar and Frank retrieves it. After that, Helen's slip mysteriously disappears because she is obviously not wearing it (since the girls cut her dress, she would've had to have pinned it back up or else it would be visible). Also, Helen's purse is too small to stuff it into and Frank didn't bring anything to carry it in.
Visible crew/equipment: You can see the cameraman, camera, and a crew member reflected in the school bus window as it drives off. (01:17:20)
Continuity mistake: When Helen and Frank are walking home after their first date you can see that they are surrounded by people. When the shot changes all the people have disappeared and Helen and Frank are almost completely alone.
Continuity mistake: Envelopes to Helen are shown with an address of 1034. But in scenes showing the front door, the address is 346.
Factual error: In the scene where Frank is giving Helen a ride home from the Japanese Restaurant, when they drive across the Golden Gate Bridge, you see them pass three support towers when there are only two on the real bridge. There are also exit signs that disappear just before they pass the third tower.
Suggested correction: This is wrong, they are not crossing The Golden Gate Bridge. They are crossing The Bay Bridge, when you realise this it makes sense as the Bay Bridge is a bridge that has 4 suspension towers.
Continuity mistake: When they all first move into the new house after the wedding, they are scrambling to get settled into their rooms when the lights go out. Helen and Frank hand out candles and Helen asks Greg to take some downstairs. After he heads downstairs, a voice is heard remarking, "Where's 6-blue-B?" According to Frank's chart, Greg is 6-blue-B. Also, the voice-over begins just before the shot switches off of Greg heading downstairs.
Continuity mistake: A bottle of ketchup on the lazy Susan (beside the shorter bottle of chili sauce) keeps appearing and disappearing between shots, prior to the dinner starting. (00:51:45)
Continuity mistake: When the doctor examines Phillip (the first night the whole family is in the new house) he wipes and puts away his thermometer, then does the same motions again.
Continuity mistake: In the scene where Frank brings Helen home to meet his kids, he asks Mike to fix them a drink. He does, but only fills Frank's glass halfway. When Rusty takes the drinks to them, the glass is full.
Continuity mistake: When Helen and Frank go to the bar on their first date, Helen asks Frank to get her some cigarettes. Frank returns with six packs of cigarettes, three in each hand. Helen then claims that she doesn't smoke, and Frank puts all six packs into one hand to accept a drink. When we next see Frank's hand he has three packs of cigarettes. Finally, the cigarettes disappear completely.The cigarettes couldn't have fallen on the floor because we see the floor in different shots. And, as Helen and Frank are standing in the middle of the bar, surrounded by people, Frank has no place to put the cigarettes.
Factual error: When Mike walks away at the end he is in uniform. No recruits are issued uniforms until they arrive at camp.
Other mistake: In the opening scene, where Henry Fonda is standing on the deck of the carrier, he is looking at his watch and he says "Zero Nine Hundred" If you look closely, the sweep second hand on the watch never moves from 4:00.
Revealing mistake: When Philip is in the bathroom at the new house Mike puts toothpaste on his toothbrush and then Philip smiles to reveal missing teeth. Look closely at Philip's teeth and you will see that they are not missing at all - there is black paint on his teeth to make it look like they are missing. (01:14:40)
Continuity mistake: Scenes showing the newborn until the end switch blanket colors back and forth from blue to pink.
Factual error: At the start of the movie, Frank is shown departing the Enterprise along with enlisted men. On large ships such as carriers, there are two separate brows (i.e., "gangplanks"), one for officers and one for enlisted personnel.
Continuity mistake: When Frank brings Helen to his house to meet his children there jam smudged on the front window and it changes in between shots.
Continuity mistake: Van Johnson has jam and ink rubbed on his uniform by the children, but those stains are completely gone in the next scene when he accompanies Henry Fonda and the daughter to the dispensary.