Abstract An analysis of our experience with 48 patients having bronchiolar or alveolar cell carcinoma is reported. The remarkable biological variability of this peripheral tumor has important surgical implications. Basically, two dominant clinical presentations occur. In the less common diffuse or multinodular form, prolonged survival is infrequent regardless of the therapeutic approach. Often these patients die from respiratory compromise due to the tumor itself. In the more common localized or solitary form the prognosis for cure is good, approximating 47% or higher. Based on the material presented, lobectomy is the preferred method of surgical treatment. In patients manifesting multinodular disease, surgical resection rarely seems warranted. The concept of preserving pulmonary tissue is stressed.