When Big Daddy and Brick are talking in Brick and Maggie's bedroom about Brick's alcoholism, the audio on one of Big Daddy's lines is, "You'll hear plenty of that in the grave soon enough, but right now we're going to sit down and talk this over." The last three words in this sentence do not match the movement of Big Daddy's mouth.
After Brick tries to drive away and gets stuck, Maggie goes out to him and helps him into the house through the pouring rain. Her hair is soaking wet, but the next time we see her, it's perfectly dry and styled.
When Maggie is arriving at the birthday party, she is assaulted by her niece who throws ice cream at Maggie's legs. Maggie scoops up a teaspoonful of the mess from her legs, with the intent of smearing it in the child's face. When she reaches the child, the tiny amount of ice cream she holds has grown to considerably more than a pint.
In the opening scene, Mae is shown rehearsing the children to play Dixie when they meet Big Daddy at the airport. Initially she is shown at the front of the parade, then in the next shot she is bringing up the rear.
After Brick and Big Daddy come up from the cellar, Big Mamma says to Gooper "Take these papers away before I tear them up. I don't know what's in them; I don't want to know what's in them." Big Daddy goes outside and talks to the folks fixing the light. As he approaches the door to come into the room where Gooper and Big Mamma are arguing, you can hear her say the line "Take these papers away before I tear them up. I don't know what's in them; I don't want to know what's in them." again.
In the first scene of the film, when Brick is arranging the obstacles, his shadow is projected to the right side of the screen. After he approaches the car and drinks from the bottle, his shadow is projected to the left side.
After Doctor Baugh tells Brick the truth about Big Daddy, he leaves the scene from the balcony. However, near the last shot of the scene, you can see a shadow of a person walking behind on the balcony long after Doctor Baugh left the scene.
In the opening scene, Brick is at a sports field bearing the sign "East Mississippi High School Athletic Stadium." Later in the film, after a storm, one of the characters states that the rain has "moved across the river to Arkansas." That implies that Big Daddy's plantation is somewhere close to the Mississippi River, which run along the edge of western Mississippi. References to Gooper's law practice in Memphis and the 28,000 acres of rich land also indicate a plantation in the Mississippi Delta country, along the river in northwest Mississippi, rather than the eastern part of the state.
When Doc Baugh comes upstairs to tell Brick about Big Daddy's real condition, he examines Brick's leg and discusses football with him. In the course of that conversation, Brick alludes to a game played against "Bama State", meaning Alabama State. Bama State (Alabama State) is a historically black university in Montgomery. During the 1950s, Brick's college (presumably Ole Miss) would not have been allowed to play a historically black college. The choice of "Bama State" by the writers was a factual mistake, in that such a game could not have occurred under any circumstances in that era.
The enormous cake Big Momma brings into the bedroom - and continues to carry for the remainder of the scene - is clearly fake. Despite its size, she carries it with no effort and without it shifting on its platter. Later on, it is plain that the colored candles have nearly completely melted down, leaving streaks of wax all over the unchanged surface.