The management of malignant pleural effusion is a difficult problem. Tetracycline was probably the most commonly used sclerosing agent, but parenteral tetracycline is no longer available. This prospective study was designed to determine the efficacy of insufflated talc in producing plerodesisin patients with malignant pleural effusions. Fifteen patients managed between March 1995 and March 1997 underwent thoracoscopy and had 4 gm sterile asbestos-free talc insufflation throughout the pleural space. The mean interval between the procedure and last follow-up was 101 days(range: 25-233 days). The results of treatment were clinically and radiologically compared with pre-operative status. The results were as follows: 1. The patients were 6 men and 9 women with a mean age of 55.1 years(range: 31-74 years). The primary tumors were lung cancer in 10 patients, breast cancer in two, hepatoma in one, stomach cancer in one, and adenocarcinoma of unkown origin in one. 2. Cancer cell positive ratio was 36% in sputum cytology study and 100% in thoracoscopic biopsy. 3. Symptoms improved in 94% of patients treated by talc pleurodesis. 4. After 30 days of the procedure, there was radiologically no recurrence of plural fluid in 94% patients. 5. There were wound infection in one, respiratory failure in one. In conclusion, the insufflation of 4 gm sterile asbestos-free talc in the pleural space is an effective method to control malignant pleural effusions and patients selection is important factor for reexpansion the lung.