Objective To analyze the clinical features and diagnosis methods of 75 cases of bronchioloalveolar carcinoma (BAC) confirmed pathologically. Methods A total of 75 BAC cases from January, 2001 to June, 2010 were retrospectively analyzed. Results Among all 75 cases, the ratio of male and female was 1:1.34; the mean age was 56.5 years; the smoking patients accounted for 12%. All 75 patients had chest CT scanning. Among which, 58 patients displayed solitary tubercle, 8 patients widespread tubercles, and 9 patients infiltrating inflammation. Transthoracic biopsy guided by CT or ultrasound were performed in 26 patients, and 22 patients got definite diagnosis of BAC. Nine patients underwent bronchofibroscopy and only one got definite diagnosis. Postoperative biopsy was performed in 52 cases to get the definite diagnosis of BAC. Conclusion The clinical features of BAC are different from other lung cancers. CT scan may be beneficial in diagnosis of this disease. Transthoracic biopsy can elevate diagnosis accuracy of BAC.