Occurrence of the carpal tunnel syndrome in pregnancy was studied by examining 100 consecutive obstetric admissions. Twenty-one patients reported paresthesias or hypesthesia in the median nerve sensory distribution of the hand during the pregnancy; eight of these had decreased sensation subjectively at the time of examination one to three days after delivery; two had trophic changes, loss of sudomotor function, thenar atrophy, and decreased two-point discrimination; and one had a delay in motor conduction time across the carpal tunnel. Of the 21 patients, 18 became asymptomatic before or shortly after delivery. The remaining three were asymptomatic three months after delivery. We conclude that the incidence of symptoms is probably greater than usually appreciated, but that few patients require treatment. Steroid injection may occasionally be necessary, but the need for surgical intervention is rare.