Between 1975 and 1990, 104 male patients with a total of 106 breast cancers were treated at Memorial Hospital or the Ochsner Clinic and their records reviewed. The patients were followed for a median of 67 months (range, 0.5 to 14.4 years). Analysis of the frequency distribution by stage showed that 16 (17%) patients were stage 0 and 26 (27%) patients were stage I. The median duration of symptoms before diagnosis was 18 weeks (mean, 5 weeks; range, 1 to 156 weeks). Modified radical mastectomy was undertaken in 71 (67%) patients. The actuarial 5-year relapse-free survival for the entire group was 68% and the actuarial 5-year overall survival was 85%. Relapse-free survival at 5 years for axillary node-negative patients was 87% and for node-positive patients was 30% (p less than 0.001). Overall survival figures for the same subsets showed a 5-year survival of 100% for the node-negative subset and 60% for the node-positive subset. On multivariate analysis, the most powerful predictor of outcome in men was the status of the axillary lymph nodes, and the only prognostic factor that added significantly to this predictive power was the duration of symptoms. Patients who sought treatment less than 6 months after the onset of symptoms experienced a significant survival advantage when compared with patients whose symptoms were present for more than 6 months (p = 0.03). The profile of the stages at diagnosis, the treatment approach, and the survival rates approximate those reported in series of female breast cancers, and overall, the two diseases are remarkably similar.