Although osteopenia is often reported as a complication of type 1 diabetes mellitus, its frequency and severity remain unclear, and studies of bone mineral density in type 1 diabetics have yielded conflicting results. We measured bone mineral density at the lumbar spine and femoral neck in 88 Spanish adults with type 1 diabetes mellitus responsible for moderately severe complications. Mean age (+/- SD) was 28.9 +/- 8.8 years, and mean disease duration was 11.2 +/- 6.4 years. As compared to normal Spanish adults, bone mineral density was decreased in the patients at the lumbar spine (Z-score, -0.32 +/- 1.08; P < 0.001) but not at the femoral neck (Z-score, -0.21 +/- 1.03; P non-significant). The magnitude of bone loss in the diabetics was small (T-score, -0.38 +/- 1.13 at the lumbar spine and -0.37 +/- 1.08 at the femoral neck). Only three patients met WHO criteria for osteoporosis at one or both measurement sites. Patients with retinopathy (n = 37) had lower lumbar spine bone mineral density values than patients without retinopathy; however, this difference was no longer present after adjustment for age and disease duration. Bone mineral density values were similar in patients with (n = 13) and without microalbuminuria. Our findings suggest that bone loss is not a major problem in younger type 1 diabetics with short disease durations and no severe diabetic complications.