Background: Interferon gamma (IFN-¿), a cytokine produced by a variety of cells is involved in the immune response against M.tuberculosis. It activates the production of other cytokines & molecules that kill MTB. IFN-¿ also has diagnostic role in identification of active and latent TB. Objective: To determine the level of IFN-¿ in the blood of TB patients. Methods: 91 subjects were selected, including 54 active TB patients and 37 healthy controls. IFN-¿ conc. was determined in their blood by ELISA technique. Results: In TB patients, Mean+SD of IFN-¿ was 48.69+28.78 while it was 12.99+5.70 pg/ml in control group (p