An open non-comparative multicenter study-observation according the program involving 190 patients (mean age--62.3 +/- 9.7 years) with benign prostatic hyperplasia (BPH) and severe urination disorders was performed. All of the patients received alfuzosin (dalfaz SR) 10 mg daily for 12 months. The primary criterion for evaluation of treatment effectiveness was the change of the total IPSS score. As secondary criteria, change of QoL score, total number of urination per day and subjective patient's satisfaction with the treatment results were registered. Safety was assessed by recording the adverse events. The treatment led to the progressive decrease in the total IPSS score--from 16.4 +/- 4.8 at baseline to 7.7 +/- 2.6 at the final visit (P < 0.001). The average QoL score has decreased by 67% - from 3.9 +/- 1.1 to 1.3 +/- 0.7 at the end of the study (P < 0.001). In general, 94.2% of respondents positively assessed the results of treatment. The frequency of urination at night has decreased by 56%. Adverse effects (dizziness and slight fatigue) were recorded only in 1 (0.5%) patient. The present study has demonstrated a high efficacy and a favorable safety profile of dalfaz SR at a dose of 10 mg in the treatment of patients with BPH. Of particular note is the high proportion of patients who continued to receive the drug for 12 months, showing a good tolerability ofdalfaz SR and high treatment compliance.