When Annie drives Alvy home from the tennis game, she parks behind a red car. The next cut, showing the two exit the vehicle, shows them parked behind a blue car.
After Alvy deals with the spiders at Annie's, Annie says she thought she heard someone else with Alvy when he answered her phone call in the previous scene. He was with Pam (Shelley Duvall), so Alvy makes up a lie about having his television on. However, Pam had been perfectly quiet during Annie's call.
As Alvy is trying to kill the spiders, 4 toothbrushes in a holder can be seen in the bathroom.
In the beach house, Alvy and Annie are cooking half a dozen lobsters, which makes for a funny situation visually, but is three times more than they can eat.
Annie's "thought" subtitle, "I dabble? Listen to me. What a jerk", appears before she says she dabbles. However, this should not be considered a Goof as many people actually think before they speak.
A boom microphone is visible in the cabin bedroom scene. This is reportedly deliberate.
When Annie is driving on the freeway with Alvy, a police cruiser can be seen in the background holding back traffic.
Given the sound of the roasting pot on the stove, there is no water in it when Alvy drops in one of the (dead) lobsters.
Not only is the red station wagon gone when Annie parks her VW, but when the camera changes, it is evident the location is different. As they exit the car, she has parked directly in front of a street sign, which was not there as she pulled into the space. There is also a pole with a small fence surrounding its base, that would have been in the parking shot if they were at the same location.
Near the end of the film when Annie and Alvy meet outside the Los Angeles restaurant, the crew is reflected in Annie's glasses.
There is a New York State flag on the University of Wisconsin's auditorium stage. (The scene was shot at Manhattan's Fashion Institute of Technology on 7th Avenue.)
Marshall McLuhan, whom Alvy brings over to refute the boorish professor in the theater, himself makes an inane comment; accusing the guy of suggesting his "whole fallacy is wrong". A fallacy, by definition, is something that is wrong.
There is no such thing as kosher ham. When Annie takes Alvy to meet her family at dinner, he sees her mom as viewing him as the "classic Jew", to which she and Annie should already have known that Jewish people do not eat pork.
When Annie Hall sings "It Seems Like Old Times," she sings "walk" twice. It should have been:
Seems like old times Having you to walk with Seems like old times Having you to talk with....
Seems like old times Having you to walk with Seems like old times Having you to talk with....