Some formulations possess the ability to stimulate or suppress immune system thus may be important in controlling various disease condition or lead to undesirable prospect. Studies on immunomodulatory agent can leads to isolation of acceptable and reliable pharmacological agent with wider application. This study evaluate the immunostimulatory activity of Polyherbal Formulation (PHF) on Th1/Th2 cytokines secretion and cell mediated immune response in Wistar Rats. Twenty four (24) Wistar rats were randomly divided into six group and each group contains four rats. Group 1 received normal saline as normal control, Group 2 received Levamisole Hcl as positive control, Group 3 received Cyclophosphamide as negative control, while Group 4 - 6 received different concentration of aqueous extract of PHF. Blood was collected and processed to obtain a serum. The serum was used for Th1 (IL-2, IFN-γ) and Th2 (IL-4, IL-6,) cytokines analysis using ELISA techniques. Keyhole Limpet Hemocyanin was used as antigen to induce Delayed type hypersensitivity (DTH) response. Footpad thickness was measured using digital vernier calliper. There was significant increase in serum concentration of IL-2, IFN-γ, IL-4 and IL-6 across the treatment groups with increase in dose of PHF (p < 0.001). There was significant increase in DTH response across the treatment groups in dose-dependent manner (p< 0.001). The PHF has immunostimulatory activity on Th1/Th2 cells thus induce the secretion of the cytokines. It increase DTH response thus can be useful in immune response involving T lymphocytes. The formulation could be useful in managing immunosuppressed conditions due to its immunomodulatory potential.