A cross sectional study was performed in order to evaluate the treatment conditions and medical outcomes among 131 prevalent hemodialysis patients (57% males; mean age 66 +/- 12 years) in Huesca and Teruel. Data were collected at 5 hemodialysis units in Huesca and Teruel. Diabetes mellitus, at 30 percent, was the most common cause of renal insufficiency. The mean (+/- SD) urea-reduction ratio (URR) was 66.0 +/- 8.8%. We observed that 56.5% of the population reached an URR higher than 65%. The duration of dialysis session was 220 +/- 24 minutes, with a rate of blood flow 297 +/- 47 ml/min. 36% of patients used high-flux membranes. The patterns of vascular access were: 69% arteriovenous fistula, 5% synthetic graft and 26% catheter. Eighty nine percent of patients were treated with erythropoietin. The mean dose of erythropoietin was 109 +/- 62 UI/Kg weight/week. Thirty nine percent of patients had haemoglobin below 11.0 g/dl (mean 11.2 +/- 1.4 g/dl). Ferritin levels were below 100 ng/ml in 24% of the patients and 25% showed a transferrin saturation index below 20%. Fifty percent of patients were receiving vitamin D. Serum calcium 9.3 +/- 0.8 mg/dl; phosphorous 5.5 +/- 1.5 mg/dl; calcium-phosphorous product 51.5 +/- 14.3 mg/dl; PTHi 433 +/- 459 pg/ml; and aluminium 26.8 +/- 14.5 mcg/l were the mean of main biochemical markers of mineral metabolism. Sixty eight percent of patients had phosphorous levels below 6.0 mg/dl. Thirty seven percent of patients had aluminium levels lower than 20 mcg/l. The mean serum albumin was 3.4 +/- 0.4 g/dl. Forty five percent of patients had albumin below 3.5 g/dl.