The purpose of this prospective randomized study was to investigate the effects of the extract of Acanthopanax senticosus (AS extract), a widely used oriental herb, on bone remodeling and bone mineral density in Korean postmenopausal women. A total of 81 postmenopausal women with osteopenia or osteoporosis, an age of less than 65 years, were enrolled in the study. Subjects were randomly assigned to two groups: (1) the control group (n = 40), calcium intake (500 mg per day), and (2) the treatment group (n = 41), calcium (500 mg per day) plus AS extract (3 g per day). After treatment with AS extract for 6 months, the AS extract group showed a significant increase in serum osteocalcin levels compared with the control group (P = 0.041). However, no significant changes in bone mineral density were observed by dual-energy X-ray absorptiometry (DXA). AS extract was generally well tolerated, and no differences were observed between the two groups in terms of adverse events. This study suggests that AS extract supplementation may have beneficial effects on bone remodeling in Korean postmenopausal women and that it has no significant adverse events.