A retrospective review over 6 yr of patients presenting to the hand clinic was performed to identify cases of postoperative brachial plexopathy (PBP) and to assess both prognosis and early indices of prognosis. Over this period (1989-1995), 22 patients were referred by the hospital's surgical departments to the hand clinic because of PBP. Eight cases followed open heart surgery (OHS) and 14 followed non-cardiac surgery (NCS). Median full recovery took 10 (range 4-16) weeks and 20 (8-50) weeks, respectively. Long-term follow-up revealed one OHS patient with residual tingling and three NCS patients with residual weakness. Brachial plexopathy after median sternotomy was characterized by a predominance of sensory complaint in the lower roots of the plexus. Injury after non-cardiac surgery was reflected by a predominance of motor deficit in the upper and middle roots. Brachial plexus injury after cardiac surgery carries an excellent prognosis for full functional recovery. Although the limited number of cases precludes statistical substantiation, the data suggest that the prognosis of PBP after non-cardiac surgery may be worse in males, diabetics, those with injury to all roots of the plexus and, when in addition to the motor deficit there is sensory loss and pain or dysaesthesia. At a 1 week "prognostic milestone", 79% of NCS patients with significant symptomatology enjoyed complete recovery although this took as long as 5 months to 1 yr in 50% of patients. At a 6-8 week "prognostic milestone", 50% of those who had not yet had improvement in the motor deficit suffered residual neurological deficit. All patients recovered to a significant extent even when recovery was not complete and none suffered from late deterioration or chronic pain.