Abstract: T helper subset response to P. falciparum is well documented, however there is little or no information with respect to P. vivax, though it is associated with high rate of morbidity and hospitalisation. In the present study circulating IL-2, IFNγ, IL12, IL10, IL-4 and TNFα concentrations were investigated in patients with mild and severe P. vivax infection. Hemoglobin status, Packed Cell Volume (PCV), serum zinc and vitamin A were also evaluated. Hemoglobin concentration was low, as expected and further decreased significantly in 1 week of malaria and was negatively correlated with TNFα, suggesting a role for this cytokine in the pathogenesis of anemia and destruction of RBCs. The initial level of TNFα was significantly correlated with IL10 concentration (regression analysis) thus indicating an anti-inflammatory role for IL10 in the regulation of TNFα. Initial concentration of IL2, IL12 and IL10 were higher in the mild malaria and were associated with low parasite density. In contrast, high concentration of IFNγ was associated with low IL2 levels in severe malaria, suggesting that in severe malaria there is an inability to mount a TH1 response (IL-2) and to maintain an adequate balance of Th1/Th2 response. Both serum zinc and vitamin A were low in mild malaria, however, with increasing severity, serum zinc concentrations increased which could be an adaptive response to potentiate the immune response as reflected by the increase in IFNγ and TNFα. Though there was no significant correlation, higher vitamin A levels were associated with low IL-2 levels implicating vitamin A in down regulating Th1 response.