Although there is ample evidence supporting the effectiveness of physical activity in the prevention and treatment of osteoporosis, there are no previous studies to examine the effect of office-based brief high-impact exercise (HIE) on bone mineral density (BMD) in healthy premenopausal women. This study evaluated the effects of office-based HIE on BMD in healthy premenopausal Japanese women. Ninety-one healthy premenopausal women were randomized to receive stretching exercise (SE) or HIE (stretching, along with up to 5 × 10 vertical and versatile jumps) for 12 months. The BMD of the lumbar spine and proximal femur was measured using dual-energy X-ray absorptiometry. Several cardiovascular risk factors and leg strength also were assessed. An accelerometer-based recorder was used to measure daily impact loading in four 1-week samples. The progression of the HIE program was ensured by the accelerometer. Thirty-three women (71.7%) in the SE group and 34 (75.6%) in the HIE group completed the study. There was a significant difference in the change in the femoral neck BMD between the groups in favor of the HIE group [0.6% (95% CI: -0.4, 1.7) vs. -1.0% (95% CI: -2.2, 0.2)]. Adiponectin, LDL, HDL, and the leg strength of participants in both the groups improved during the intervention. These finding suggested that office-based brief HIE can be recommended for premenopausal women for preventing bone mineral loss.