This study was done on 44 patients with pulmonary tuberculosis. They were 33 (75%) males, and 11 (25%) females. Their age ranged from 17-53 years (mean ± SD = 37.64 ± 9.71 years). They were classified according to chest x ray into 3 groups, group A : 15 patients with far advanced lesion, group B: 15 patients with moderately advanced lesion, and group C: 14 patients with minimal lesion. The study also included 18 age and sex matched healthy individuals as a control. All are subjected to thorough history taking, full clinical examination, complete blood count (CBC), Erythrocyte sedimentation rate (ESR), chest x ray, tuberculin test, and bacteriological examination of sputum for Mycobacterium tuberculosis including smear stained with Ziehl Neelsen (ZN) stain and culture on Lowenstein Jensen (LJ) medium. The circulating levels of IL-18 and osteopontin (OPN) were also measured by enzyme linked immunosorbent assay (ELISA) method. The results showed that the circulating levels of IL-18 and OPN were significantly higher in patients with pulmonary tuberculosis than in the control group (both P