Blind percutaneous pleural biopsy by Castelain needle was performed on patients with undiagnosed exudative effusions, with non-diagnostic cytology, and a clinical suspicion of tuberculosis or malignancy. Results: From 7/2008 to 2/2009, 105 cases of exudative pleural effusions (72 male and 33 female patients) were admited and perfomed by blind percutaneous pleural biopsy by Castelain needle.