To investigate bone mineral densitometry findings in patients with normocalciuric urinary system stone disease, we compared 150 patients with normocalciuric calcium stone disease (group 1) and 60 subjects of a control group (group 2). The patients were compared according to bone mineral content (BMC), bone area (BA), bone mineral density (BMD), T-score and Z-score values of femur neck, total femur and lumbar spine (L2-L4) by dual energy absorptiometry. We found that 76.6% of the patients in group 1 and 20.0% in group 2 had low BMD; 11.3% of patients in group 1 had osteoporosis and 65.4% had osteopenia. In the control group, there was no osteoporosis, but 20.0% of the subjects had osteopenia. In group 1, there was hyperoxaluria in 26.0% of patients, hypocitraturia in 15.3% of patients, hyperuricosuria in 6.0% of patients, both hypocitraturia and hyperoxaluria in 8.6% of patients in a 24-h urine analysis. Urine analysis was normal in 44.0% of patients. Our results showed a severe loss of bone mass in patients with urinary system normocalciuric calcium stone disease. Thus, the necessary precautions concerning bone mass protection should be taken and the patients should be informed about this issue.