OBJECTIVE To evaluate the efficacy and safety of talc poudrage pleurodesis via semi-rigid medical thoracoscopy in the treatment of malignant pleural effusions, as well as the factors that may influence the outcomes. METHODS A series of 27 patients with malignant pleural effusion underwent medical thoracoscopic talc poudrage pleurodesis between July 2005 and September 2007 in Peking University First Hospital. RESULTS There were 16 male and 11 female patients in the series, the average age being 65.2 years. All the patients had documented malignant pleural effusions, including 16 cases of adenocarcinoma, 6 of malignant mesothelioma, 2 of squamous cell carcinoma, 1 of lymphoepithelioma-like carcinoma, 1 of small cell carcinoma and 1 of undifferentiated lung cancer. Thirty days after the procedures, complete successful pleurodesis was achieved in 22 cases, and partial successful in 4 cases. Pleurodesis was not successful in one case. Overall successful rate was 96.3% (26/27). The average duration of thoracic tubing was 6.85 days. Chest pain, fever and an increase in peripheral WBC after the procedure occurred in 19(70.4%, 19/27), 21(77.8%, 21/27), and 12(44.4%, 12/27) cases respectively. No respiratory failure occurred. CONCLUSIONS Medical thoracoscopic talc poudrage pleurodesis is a safe and effective method for the treatment of malignant pleural effusion.