The aim of the study was to assess closed pleural biopsy (CPB) as a diagnostic method of pleural effusion. CPB using Cope needle was performed in 62 patients, proceeded by ultrasound examination. It helped to obtain specimen for histological and microbiological examination even with cases of small amount of fluid. In all 62 patients CPB enabled to diagnose 13 cases with neoplasmatic effusions (majority being adenocarcinomas) and 16 cases of tuberculosis in histological and/or microbiological examination. There were 33 cases with non-specific inflammatory changes. In 7 patients we confirmed neoplastic pleural infiltrates in cytological examination of pleural effusion. In 26 patients videothoracoscopy (VTS) was carried out and 20 of those had post-inflammatory changes. In 4 cases, however we confirmed neoplasmatic effusions and in next 2 cases--tuberculosis. Closed pleural biopsy proves to be an efficient method in diagnosis of Tuberculosis and malignant pleural effusions. However, in 23% of cases with post-inflammatory changes, malignancy and tuberculosis were undiagnosed. This in turn implicates the necessity for further diagnostic procedures including VTS.