Considering the autonomic function of cerebellum, it is a potential neural area for immunomodulation. Though the role of fastigial nucleus (FN) and vestibulocerebellum on immunomodulation has been investigated, the results are contradictory. In the present study the role of posterior cerbellar vermis (PV) and FN on some immunological parameters such as TC and DC of WBC, leukocyte adhesive inhibition index (LAI) of splenic mononuclear cell (MNC) and phagocytic activity of peripheral WBC by fluorescence activated cell sorter (FACS) were investigated after two and three weeks lesions of PV (lobules VII, IX and X) and FN by aspiration technique in male rats. The TC of WBC was decreased after two weeks of PV+FN lesioned rats compared to that of sham lesion and control rats. The percentage neutrophil and eoisinophil counts were increased and the lymphocyte count was decreased after two weeks of PV+ FN lesioned rats compared to that of sham operated and control rats. The phagocytic activity of blood WBC and LAI of splenic MNC were increased after two weeks of PV+FN lesioned rats compared to that of sham lesioned and control rats. After three weeks of PV+FN lesioned these immunological parameters were regain to the normal level. The results indicate that the combined lesion of PV and FN induced enhanced immune responses but this effect is transitory.