Aqueous leaf extract of Morus alba was evaluated for the immunomodulatory activity. Wistar rats were used as the specimen. The extract is tested for hypersensitivity and hemagglutination reaction using sheep red blood cells (SRBC) as the antigen. The Morus alba (200 & 400 mg/kg p.o) offers an increase in delayed type hypersensitivity reaction and the effect is comparable with that of the standard drug levamisole. It does not induce any significant alterations in antibody titer value. Morus alba however facilitates a considerable increase in total leukocyte, lymphocyte, neutrophil and eosinophil count. In comparison to 200 mg/kg dose, 400 mg/kg dose of Morus alba was found to induce a better immunomodulatory activity. It is inferred that Morus alba aqueous extract stimulates the innate or nonspecific immune system in a dose dependant manner and does not stimulate the adaptive immune system in mediating immunomodulatory property.