Neolamarckia cadamba (Roxb.) Bosser Miq., holistic tree, well narrated in Charak Samhita and Sushrut Samhita. Traditionally different parts of N. cadamba has been used by many communities and tribes to treat sour throat, cough, fever, infections and inflammation. Present work concern with study of immunomodulatory activities of hydro-methanolic extract (HME) of N. cadamba bark with reference to humoral and cell mediated immune responses of experimental animals. On the basis of mean body weight (g) of Wistar albino rats, their healthy status, change in their behavior, skin and fur texture, four groups- Group-I (control), Group-II (125 mg/kg HME), Group-III (250 mg/kg HME) and Group-IV (500 mg/kg HME) containing six animals each were made to determine mean serum antibody titer of treated and control groups against Salmonella typhimurium ‘O’ antigen using indirect ELISA. Determination of in vitro cell mediated immune response was done by MTT assay using optimum concentration (5 µg/mL) Con A with various concentration of HME (20-500 µg/mL). Result suggested various doses of HME (125/250/500 mg/kg b.wt) causes significant increase (p < 0.01) in antibody titer when compared to the control group, which concludes enhanced humoral immune response. Result suggested that different concentrations of HME bring about significant increase (p < 0.01) in proliferation of splenocytes, depicting enhanced cell mediated immune response. Study concludes immunostimulatory potential of HME of N. cadamba bark and can be possibly used in drug and food preparation.