Goofs

At around 27 minutes Mommy rips the drawing twice in different directions,but later when Elias finds the drawing it is only ripped one time.

At 49 minutes, the children are being driven by the police in their car. It's very apparent the car isn't moving.

Like Tom Tryon'sThe Other (1972),the audience is led to believe there are two boys and not just one. Problem is, if the viewer watches "Goodnight, Mommy" closely, there are a few points where Lukas (the pretend brother), speaks and is answered by the mother and the cops--this being an attempt to fool the viewer further. Note also that Lukas' onscreen image is slightly out of focus which suggests he isn't real. Despite all of this, the mother's behavior throughout is simply preposterous.

The female Connecticut State Trooper is wearing eagle insignias on her collar. This denotes the rank of Colonel, which in state police organizations would be the head or the superintendent of that department. She would not be out on patrol.