One hundred thirty-four consecutive patients (65 men and 69 women) underwent pulmonary resection for bronchoalveolar carcinoma. Mean age was 65 years. Lobectomy was done in 100 patients, pneumonectomy in 10, segmentectomy in 5, and wedge excision in 19. Only 10 patients had lymph node metastases (7.5%). The neoplasm was solitary in 111 patients (82.8%); 97 were in stage I, 4 were in stage II, 9 were in stage IIIa, and 1 was in stage IIIb. There were two operative deaths (1.5%). Thirty-nine complications occurred in 31 patients. Median follow-up was 5.1 years. Recurrent bronchoalveolar carcinoma developed in 45 patients. Five- and 10-year survival for patients in stage I was 75.2% and 62.0%, respectively. Survival for patients with T1 N0 M0 neoplasms was identical to expected survival and was 90.5% at 5 years, as compared with 55.4% for patients with T2 N0 M0 disease, only 35.9% for patients with multiple bilateral disease, and 0.0% for patients with bilateral disease (p less than 0.0001). Other significant factors adversely affecting survival included the presence of signs and symptoms, diffuse malignant invasion, mucin-producing tumors, and the histological absence of scar. We conclude that bronchoalveolar carcinoma has a unique natural history that is more influenced by local neoplastic processes than by lymph node metastases. Early aggressive pulmonary resection is safe and offers the potential for cure. The presence of bilateral cancer, however, is ominous.