Introduction: The study aimed to evaluate the long-term efficacy of treatment with extract of Serenoa repens (Prostamol Uno) in patients with lower urinary tract symptoms (LUTS) induced by benign prostatic hyperplasia (BPH). Patients and Methods: We studied 120 patients with mild or moderate LUTS induced by BPH, maximal urinary flow (Qmax) <15 ml with a voided volume ≧150 ml, prostate-specific antigen <4 ng/ml, and residual urinary volume <150 ml, treated daily for 24 months with one capsule of 320 mg ethanolic extract of Serenoa repens. Results: Statistically significant improvements in the International Prostate Symptom Score (5.5 points), quality of life (QoL; 1.8 points), Qmax (5.6 ml/s), International Index of Erectile Function (IIEF; 6.4 points) and reduction in residual urinary volume were observed during the study period. The mean prostate volume at 24 months was 36 ml, compared to 39.8 ml at baseline. Conclusions: Long-term treatment with 320 mg ethanolic extract of Serenoa repens proved to be efficient in reducing urinary obstruction, improving symptomatology and QoL of BPH patients. It also had a positive effect on sexual function, demonstrated by the statistically significant increase in the IIEF.