Bronchioloalveolar cell carcinoma accounts for less than 6% of all primary lung cancer but has distinct clinical and radiological features and unusual pathologic appearance. The characteristic features are its peripheral location and tendency of rapid progression to diffuse type via aeroginous and lymphatic route without surgical intervention. Among them, mucin secretory type bronchioloalveolar cell carcinoma is the rarest and most distinctive. We experienced a case of mucin secretory type bronchioloalveolar cell carcinoma in a 47 year old female with roentgenographic findings of chronic progressive pulmonary consolidation with muliple cavities.