A rare complication of oral contraceptive therapy is the induction of chorea. Cases (5) of chorea in patients receiving low- or high-dose estrogen-containing contraceptives were described. All patients were nulliparous, young (average age 19 yr), and became symptomatic shortly (average of 5 wk) after initiation of contraceptive therapy. Patients (2) previously suffered an episode of Sydenham chorea; 1 experienced chorea in the course of Henoch-Schonlein purpura; and 2 had a history of congenital cyanotic heart disease without chorea. Dyskinesia resolved in all patients upon discontinuing the medication. Patients with preexisting striatal abnormalities appear more susceptible to oral contraceptive-induced chorea which is reversible on drug discontinuation. The mechanism of oral contraceptive-induced chorea is unknown, but clinical and experimental data suggest that it involves altered central dopaminergic activity.