Background: Our study was designed to determine bone mineral density (BMD) in patients beginning hemodialysis (HD) treatment, a possible correlation with the duration of renal failure prior to treatment, a possible correlation with the basic disease and the association with the concentration of intact parathormone (iPTH). Methods: Our prospective clinical trial included 50 patients beginning HD treatment. Cortical bone mineral density (BMDc) was measured at the left femoral neck and trabecular bone mineral density (BMDt) in the region of the lumbosacral spine. Bone mineral density (BMD) was measured by quantitative digital radiography using a Hologic 2000 plus device belonging to the third generation of densitometers based on dual-energy X-ray absorptiometry. Results: In patients (PTS) beginning HD, the average BMDc was 82 ± 15% of BMDc in a healthy population of corresponding age and sex. The average BMDt was 91 ± 16% of BMDt in a healthy population of corresponding age and sex. The difference was statistically significant (p < 0.05). There is a negative correlation between iPTH and BMDc r = –0.34 (p < 0.02). Patients with chronic glomerulonephritis (GN) had a statistically significantly higher BMDc (g/cm<sup>2</sup>) (p < 0.01) than those with analgetic nephropathy (AN). PTS with AN have lower BMDc (g/cm<sup>2</sup>, %) (p < 0.02) and BMDt (p < 0.005) than the rest of the PTS, iPTH in PTS with AN is higher than in the rest of the PTS (p < 0.05). Conclusions: In PTS at the beginning of HD, BMD is lower than in healthy people of corresponding age and sex. This means that BMD already decreases prior to HD. BMDc was statistically significantly lower than BMDt (p < 0.00005). PTS with AN have lower BMD than those with GN and all remaining PTS. A negative correlation between iPTH and BMDc was found.