This study was undertaken to investigate the impact of Mycobacterium tuberculosis (M. tuberculosis) infection on in-vitro production of tumor necrosisfactor alpha (TNF-a), soluble CD8 (sCD8) and soluble IL-2 receptor (slL-2R) by peripheral blood mononuclear cells (PBMCs) from children with pulmonary tuberculosis (TB) versus controls.PBMCs from 8 children with newly diagnosed pulmonary TB were stimulated with PHA and LPS either separately or in combination. Five healthy children and 4 adults were used as controls. Cell free supernatants were assayed for the presence ofTNF-a, sCD8 and slL-2R with a sandwich enzyme- linked immunosorbent assay (ELISA).Although the median of TNF-a production was significantly higher in the unstimulated supernatants of patients (42.5pg/ml, 20.0-320.0) when compared to controls (15pg/ml, 0-90.0) (p<0.05) determination of sCD8 and slL-2R levels revealed no significant difference between the patients and controls.Our findings indicated that PBMC obtained from children with TB spontaneously secreted high levelsof TNF-a which may exert immunoregulatory effects and thus mediate some of the clinical manifestations of tuberculosis.