The leaves of Sida acuta Burm. f. (Malvaceae) has been reported to possess potent anti- inflammatory, anti- plasmodial and anti-microbial activities. The relationship of these bioactivities and immune responses lead to the evaluation of the immunomodulatory activity of Sida acuta Burm. f. leave extract and fractions. This our study was done to determine the immunomodulatory activity and chemical study of methanol leave extract and fractions of Sida acuta Burm. f. The immunomodulatory evaluation was done by invivo Delay Type Hypersensitivity reaction (DTHR) in the body and in vitro measurement of phagocytosis of killed Candida albicans by the phagocyte polymorphonuclear leucocytes using slide method. Acute toxicity, phytochemical and GC-MS analysis were also performed. The DTHR tested in the blood with T-cells in mice showed that the extract and its fractions caused a delayed hypersensitivity response in 24hrs which was very significant (P ? 0.05) in the n- hexane fraction of the extract when compared to the control group at the dose of 100mg/kg. The in vitro studies showed a very significant difference (P ? 0.05) in the positive control group (LEVA) at concentration of 50, 100 and 200µg/ml, in crude extract (SrE) at concentrations of 50, 100 and 200µg/ml, n- hexane fraction 50, 100 and 200µg/ml, Ethyl acetate fraction at 200µg/ml and Absolute methanol fraction at 100µg/ml and also have high percentage phagocytic stimulation (PPS). The acute toxicity test did not cause clinical signs or death within 24hours post treatment in all doses tested and highest dose of 5000mg/kg. Phytochemical analysis revealed the presence of flavonoids, saponins, alkaloids, triterpenoids, tannins, steroids and cardiac glycosides. GC-MS analysis of fraction with highest activity was carried out on n-hexane fraction which showed the presence of some compounds like hexadecanoic acid, 2-hydroxy-1 (hydroxymethyl) ethyl ester, 3,4-seco-5alpha-cholestan-3-oic acid,4-hydroxy-4-methyl epsilon-lacto