In 192 patients following median sternotomy during from 1978 to 1988, we studied the incidence, cause, prognosis and correlation of brachial plexus injury and fracture of the first rib as complications of median sternotomy. Four brachial plexus injuries were identified, an incidence of 2.1%, seven first-rib fractures were identified, an incidence of 3.6% and one patient had both complications in this series. Symptoms of this patient were more severe and difficult to improve than those of patients without first-rib fracture. Stretching of the nerve by the displaced first rib, ischemia of the nerve by pressure on it, and direct injury by the fractured rib end are causes of the brachial plexus injury following median sternotomy. It is due to the difference of position of the fracture, the difference of direction and degree of the protrusion of the fractured rib end, whether presence or absence of the brachial plexus injury in patients with first-rib fracture.