Bronchioloalveolar carcinoma is a subtype of adenocarcinoma of the lung with a relatively better prognosis. We reviewed the cases of 50 consecutive patients with bronchioloalveolar carcinoma treated during a 10-year period and attempted to analyze factors related to prognosis. During the 10-year study period, the prevalence of bronchioloalveolar carcinoma relative to adenocarcinoma of the lung remained steady. The subjects included 32 male and 18 female patients with mean ages of 64.7 years and 55.1 years, respectively (p = 0.0030). The preoperative radiographic findings included 40 cases of localized and 10 cases of diffuse bronchioloalveolar carcinoma. The clinicopathologic TNM staging included 20 patients with stage I cancer, 4 with stage II cancer, 11 with stage IIIa cancer, 3 with stage IIIb cancer, and 12 with stage IV cancer. Forty patients with clinical stage I, II, or III disease underwent operation (operability 80%). The resectability rate was 90% (36 of 40). Thirty-four procedures were considered as curative. The overall cumulative survival at 5 years was 22.2% (46.4% for stage I). Different TNM stages showed significant differences in survival time (p = 0.0001). The median survival times were 64.6 months for stage I, 48.0 months for stage II, 24.7 months for stage IIIa, 9.0 months for stage IIIb, and 4.5 months for stage IV disease. The median survival time for localized bronchioloalveolar carcinoma was 27.5 months, and the median survival time for diffuse bronchioloalveolar carcinoma was 4.3 months (p = 0.0002). The median survival time for the curative resection group was 30.6 months, and the median survival time for the noncurative resection or nonresection group was 5.8 months (p = 0.0001). On the basis of this study we conclude that (1) the prevalence of bronchioloalveolar carcinoma is quite steady, (2) bronchioloalveolar carcinoma presents at an earlier age in women, (3) bronchioloalveolar carcinoma frequently presents with lymphatic spread or systemic metastasis at diagnosis, (4) most localized bronchioloalveolar carcinomas are resectable and the prognosis with this type is better than that of the diffuse type, and (5) long-term survival correlates closely with initial roentgenographic appearance, TNM stage, and completeness of surgical resection.