We measured bone mineral density of the distal end of radius with dual energy X-ray absorptiometry, serum cross-linked N-telopeptides of type I collagen, serum bone-specific alkaline phosphatase, serum Ca, serum P, blood PCB level, blood PCQ level and blood PCDF level in Yusho. As a result, the osteoporosis group (< 70% of the young adult mean [YAM] bone mineral density [BMD]) was observed in 7.1% of the studied male subjects. And, the moderate group (> or = 70% and < 80% of YAM BMD), 16.1%, the normal (> or = 80% of YAM BMD) group was 76.8%. Also, 42.3% of all female tested subjects observed in osteoporosis group. The moderate group, 19.2%, the normal group was 38.5%. There was no difference in PCB blood level, PCQ, PCDF for men and women in osteoporosis group, moderate group, and in the normal group. Serum cross-linked N-telopeptides of type I collagen increased in the male osteoporosis group, but serum bone-specific alkaline phosphatase did not change. This study was inconclusive since the results did not determine the influence that PCB, PCQ, PCDF gave to bone density and bone metabolism.