Pleural effusion is an abnormal accumulation of fluid in lungs influencing the normal process of breathing. The aim of the present study is to investigate the clinical utility of Interferon gamma (INF-γ) biomarker in pleural fluid and serum for the differentiation of tuberculosis pleural effusion. The study enrolled 33 patients with pleural effusion classified with exudative pleural effusions that were admitted in hospital, from 2012-2015. The patients with exudative pleural effusion were categorized as: tuberculosis (11), and non-tuberculosis (22). The patients went thoracentesis and venous blood samples, under aseptic conditions, and from each subject were collected in syringe at least 30 ml of pleural fluid. The measurement of pleural fluid and venous blood were done within 24h. For measuring INF-γ was used the commercial enzyme-linked immunosorbent assay (ELISA) test. INF-γ in pleural fluid is a more accurate test for the differentiation of tuberculosis pleural effusion.