Because of the previous controversial findings in non-insulin-dependent diabetes mellitus (NIDDM), we measured bone-mineral density (BMD) by two different methods, studied biochemical markers of bone remodeling and calciotropic hormones (parathyroid hormone and calcitonin) in women with NIDDM, and compared the results with age-matched controls. Forty-seven women with NIDDM and 252 healthy nondiabetic women as controls were recruited for this study. BMD was measured by dual X-ray absorptiometry (DEXA) and by quantitative computed tomography (QCT). Biochemical markers of bone remodeling included plasma alkaline phosphatase (AP), osteocalcin (BGP), tartrate-resistant acid phosphatase (TRAP), parathyroid hormone (PTH), calcitonin (CT), and 24-h urine calcium, hydroxyproline. Diabetic patients were more obese with a higher body-mass index (BMI) than controls. Bone mass was normal in NIDDM, both by DEXA and by QCT. Biochemical markers of bone remodeling, PTH and CT were also normal. There was no statistical correlation between bone mass and any of the other measurements studied. There is no evidence that NIDDM produces any change in bone metabolism or mass.