Percutaneous transthoracic fine needle aspiration cytology (PTFNAC) of lung was done in 614 cases at the department of Pathology of Institute of Diseases of Chest and Hospital (lOCH), Dhaka, during the period from July 1994 to July 1996. A definite diagnosis was possible in 417 cases (78.83%). More than half (57.65%) of the cases were proved to have malignant diseases. PTFNAC detected malignantIesion in these patients for the first time as because no other investigation was able to establish the diagnosis. Diagnostic accuracy was 74%. Only 12(1.95%) patients developed pneumothorax and mild haemoptysis occurred in 23 (3.74%) patients. So unguided PTFNAC is a simple, time saving, safe and inexpensive method of diagnosis of peripheral lung lesions.