A bored New Jersey suburban housewife's fascination with a free-spirited woman she has read about in the personal columns leads to her being mistaken for the woman herself.

Roberta is a bored suburban housewife who is fascinated with a woman, Susan, she only knows about by reading messages to and from her in the personals section of the newspaper. This fascination reaches a peak when an ad with the headline "Desperately Seeking Susan" proposes a rendezvous. Roberta goes too, and in a series of events involving amnesia and mistaken identity, steps into Susan's life.

A paroled labor racketeer attempts to connect with his rebellious teenage daughter. Meanwhile, his deceitful former partner wants to kill him and a politically ambitious attorney wants to jail him.

A bored suburban housewife, seeking escape from her life, suffers amnesia after an accident, wakes up, and is mistaken for a free-spirited New York City drifter named Susan.