Dang-Gui-Ji-Hwang Yeum (DGJHY; an Oriental prescription), has been successfully used for the management of osteoporotic disorders in China, Japan and Korea. In this study, we have characterized the effect of DGJHY on osteoporosis-associated phenomena in ovariectomized (OVX) rats by measuring body weights and bone histomorphometries in sham, OVX and DGJHY-administered OVX rats. Light microscopic analyses showed a porous or an eroded appearance on the tibial trabecular bone surface in OVX rats, whereas those of the sham and DGJHY-administered OVX rats were composed of fine particles. The trabecular bone area and the trabecular thickness in OVX rats were significantly lower than those of sham rats. Moreover, these reductions in OVX rats were significantly reversed by the administration of DGJHY for 7 weeks, and osteoclast numbers were also significantly reduced. Although no differences were observed between OVX and DGJHY-administered OVX rats and the sham animals at the T3 level, we have found significant differences between these two groups at the T4 level. However, serum phosphorus, calcium, mechanical strength and the surface appearance of osteoblasts in the DGJHY-administered OVX rats were similar to those of OVX rats. These results suggest that DGJHY is effective at preventing bone loss in OVX rats.