Diallyl disulfide (DADS), the major sulfur compound in garlic, reduces the number of circulating T-lymphocytes, B-lymphocytes, and monocytes via activation of the hypothalamus-pituitaryadrenal axis. However, the translocation of those cells that migrate in response to DADS administration is still unclear. Therefore, in this study, we examined the effects of DADS administration on a number of lymphocyte subsets and monocyte-derived cells including macrophages (monocytes/macrophages) in spleen, the largest secondary lymphoid organ. Ten-wk-old male Sprague-Dawley rats were orally administered with DADS (dose = 20 mg/kg body weight) or equivalent volume of vehicle. The spleen was harvested 4 hr after administration, and then the splenic cells were isolated and the total number of cells was counted. T-lymphocytes, B-lymphocytes, natural killer (NK) cells, and monocytes/macrophages were fractionated by flow-cytometry and the total number of these cells was calculated. The total number of splenic cells was significantly increased by 1.18-fold after DADS administration. Among the lymphocyte subsets in the spleen, the number of B-lymphocytes significantly increased by 1.28-fold after DADS administration. The number of T-lymphocytes also showed a tendency to increase. However, the number of NK cells and monocytes/macrophages did not change after DADS administration. These results suggest that B-lymphocytes migrate from the circulation and translocate to the spleen in response to DADS administration.