AIM: To evaluate the yield of thoracoscopy in undiagnosed exudative pleural effusions. MATERIAL & METHODS: This study included 42 patients having exudative pleural effusion during one year. Males & females of age >18 years were evaluated based on clinical, radiological & diagnostic analysis of pleural fluid. Patients with undiagnosed effusion were subjected to evaluation with a semi–rigid Olympus thoracoscope & biopsy was taken. RESULTS: Overall yield of thoracoscopic pleural biopsy was 71%. Malignancy was noted in 33% with adenocarcinoma in 14 & squamous cell carcinoma in 2 patients. Tuberculosis was diagnosed in 38% of patients. The rest 29% had non–specific inflammation. CONCLUSION: Medical thoracoscopy is a safe procedure and has a good diagnostic yield in patients with undiagnosed pleural effusion, particularly when the analysis is inconclusive.