BACKGROUND: The objective of the current study was to evaluate the association between fatty liver and osteoporosis in Korean postmenopausal women. METHODS: We examined postmenopausal women who participated in a health screening test from April 2004 to November 2007. Data about lifestyle and current medical diseases and medications were collected from medical records and medical interviews. Body weight, height, waist circumference and blood pressure were measured. Bone mineral density (BMD) was measured by dual- energy X-ray absorptiometry and body composition analyzer and abdominal ultrasonography were conducted for each participant. RESULTS: One thousand two hundred forty-five postmenopausal women were selected for this study. In postmenopausal women, the spine BMD levels (g/cm(2)) were significantly different in each subjects with normal (0.819+/-0.004), mild (0.846+/-0.007), moderate (0.844+/-0.009) and severe (0.779+/-0.031) fatty liver adjusted for age (P<0.01). The proportion of osteoporosis were significantly different in each subjects with normal (39.1%), mild (30.3%), moderate (31.6%) and severe (56.3%) fatty liver. A multiple logistic regression analysis was performed to determine the association between fatty liver and osteoporosis after age, body mass index, smoking, alcohol drinking and regular exercise. In severe fatty liver compared to the normal subjects of fatty liver, adjusted odds ratio was 3.6 (95% CI 1.2~10.9). CONCLUSION: In severe fatty liver disease, the proportion of osteoporosis was increased and the bone mineral density was lower than the normal subjects of fatty liver.