Role of transthoracic fine needle aspiration cytology (FNAC) in diagnosing 170 patients of non-resolving pneumonias was studied. There were 117 males and 35 females in the age range of 3 to 72 years. The neoplastic lesions diagnosed by FNAC included 51 primary lung cancers, 6 metastatic deposits, 1 malignant mesothelioma of pleura, 1 Hodgkin's disease and 4 thymomas. Benign lesions included S6 pneumonias and abscesses of bacterial and chemical origin, 35 pulmonary tuberculosis, 2 fungal granulomas and 1 sarcoid granuloma. Aspiration cytology was inconclusive in 13 cases. The sensitivity of FNAC was 95.5 per cent in diagnosing malignant lesions accurately while the accuracy of cytological characterization was 95.3 per cent. There were no false positive reports. FNAC also helped in diagnosing sputum-negative pulmonary tuberculosis. Minor complications like syncopal attacks and haemoptysis of less than 5 mL occurred in 8.2 per cent of patient.