The present study was carried out to evaluate immunopotentiating activity of hemiparasitic sub-herbs plants belongs to Viscaceae family. Aqueous extracts of selected six Viscum plants such as, Viscum orientale Wild (8 mg/ kg body weight), Viscum nepalense Spiens (8 mg/kg body weight), Viscum ramosissimum Well (8 mg/kg body weight), Viscum angulatum Heyneex DC (16 mg/kg body weight), Viscum capitallatum Sm (8 mg/kg body weight) and Viscum trilobatum Talbot (8 mg/kg body weight) were injected intraperitoneally for 5 consecutive days to Balb/c mice and to determine the haematological parameters, body weight, lymphoid organ weight, bone marrow cellularity and α-esterase positive cells and compared with controls treated with plain water. Non-toxic V. angulatum extract (16 mg/kg) was administered to Balb/c mice (5 doses) and its effect on antibody titre, antibody forming cells, lymphoid cell proliferation, cytotoxic T lymphocyte generation and interferon γ (IFN-γ) and interleukin 2 (IL-2) levels were determined. Results indicated that there was a significant increase in white blood cells (WBC), lymphoid organ weight, bone marrow cellularity and α-esterase positive cells after intraperitoneal administration. Administration of V. angulatum extract increased antibody titre, antibody forming cells, proliferation of lymphoid cells, stimulated cytotoxic T lymphocyte as well as increased levels of IL-2 and IFN-γ. Results indicated a stimulation of immunological parameters in mice after intraperitoneal injection of aqueous extracts of plants belonging to the family Viscaceae.