This play involves the separation, then reunion, of Egeon and Emelia (husband and wife); their twin sons, Antipholus of Ephesus (A.E.) and Antipholus of Syracuse (A.S.); and their twin servants, Dromio of Ephesus (D.E.) and Dromio of Syracuse (D.S.). The family is separated at sea during a storm, 33 years before the present. Egeon, A.S., and D.S. survive together and grow up in Syracuse. Seven years before the present, they decide to search, separately, for their lost family. Emelia survives with A.E. and D.E., only to have a "rude" fisherman steal the boys from her. In sorrow, she becomes a nun in the town of Ephesus. By fate, A.E. and D.E. move to Ephesus too, though they don't know of their mother Emelia. A.E. marries Adriana, and she has a sister living with them, Luciana.
Egeon comes to the city looking for his son (A.E.) and his servant (D.E.), only to be sentenced to death for entering enemy territory. Soon after, Egeon's other son, A.S., and servant, D.S., enter the city on business. The sons and the servants (both identical twins), are easily confused by the citizens of Ephesus: Angelo the goldsmith, a female Courtesan, various merchants, and Nell, Adriana's cook and fiancee to D.E. The citizens think Antipholus and Dromio have gone mad, since they get very angry and can move from place to place like magic. Doctor Pinch, a psychiatrist, even tries to get the devil out of A.E.'s body. At the hour of Egeon's execution, Egeon recognizes his son A.E., though A.E. doesn't recognize Egeon. Simultaneously, Emelia appears from the convent with A.S. and D.S., who have taken refuge there, and the family reunites. The Duke (Solinus) pardons Egeon for entering the city, A.S. begins to court Luciana for marriage, and Emelia holds a feast to rejoice the family's reunion.