Sixty-one cases of brachial plexus birth palsies were documented in 30,451 live births at Kaiser Foundation Hospital, San Francisco, between January 1972 and December 1982, for an incidence of 2.0/1,000 births. Thirty-eight patients were evaluated in follow-up ranging from 1 year to 11 years 6 months. Associated birth traumas include facial palsy, clavicle fracture, arm ecchymosis, and cephalohematoma. The prognosis was excellent, with full recovery in 95.7% of cases. The presence of a palsy did not preclude the development of dominant use of the extremity. Right-handedness was noted in 73% of right-sided palsies. This study showed that the incidence of palsies has not declined in the past 10 years. Risk factors and associated birth injuries were similar to those in other reports. The severity of palsies has lessened, and early recovery is usual.