Multiple studies have documented reduction in peripheral bone mass in children with insulin dependent diabetes mellitus (IDDM). In this study, the bone mineral density (BMD) of the lumbar vertebrae (L2-L4) was measured by dual photon absorptiometry in 14 female and 16 male diabetic patients of age 11 to 16 years with varying clinical duration. Twenty three children between 11 to 16 years with normal anthropometric measurements between 10th and 97th percentile and no known history of metabolic bone disease served as a control group. BMD values, weight, height, body mass index, metabolic, biochemical and growth parameters of the study group were compared with those of the control group. BMD (L2 AP 0.732 +/- 0.15 gm/cm2, L2 lateral 0.534 +/- 0.09 gm/cm2 in the study group and 0.812 +/- 0.63 gm/cm2 and 0.619 +/- 0.20 gm/cm2 in the control group) and osteocalcin (10.10 +/- 3.40 ng/ml and 23.12 +/- 2.74 ng/ml in diabetes and control respectively) levels were significantly lower in diabetic patients (p < 0.05, p < 0.01 respectively). Within the study group BMD correlated positively with age but not with the duration of the disease nor with the level of metabolic control.