An attack of hypokalemic paralysis occurring in a 23-year-old woman during the immediate postpartum period of her fourth pregnancy is described. A flaccid paralysis of her extremities and markedly diminished deep tendon reflexes developed 3 hours after delivery, at which time her serum potassium level was found to be 1.7 mEq/liter. Hypokalemic paralysis has not been previously reported as an immediate postpartum complication. The pathophysiology and management of this condition are discussed, as are the treatment and follow-up of this specific patient.