In this open label prospective study in patients with category III prostatitis we assessed efficacy and safety of Sabal serrulata plant extract (prostamol Uno 320 mg) (group I, n=30) as compared to watchful waiting (group II, n=24). Efficacy was evaluated by means of NIH-CPSI, IPSS-QoL questionnaires, patients' general subjective assessment of treatment outcome, uroflowmetry and transrectal Doppler mapping (colour doppler and spectral doppler) of the prostate. Patients receiving prostamol Uno in comparison with watchful waiting group had significant improvement of mean NIH-CPSI (from 17.8 to 11.4 vs 17.1 to 16.5) and IPSS (from 13.0 to 6.3 vs 13.2 to 11.6) scores, Qmax values (from 12.9 ml/s to 17.8 ml/s vs 13.3 ml/s to 14.4 ml/s) and Doppler parameters of vascular resistance in the prostate. According to the patients' subjective assessment, moderate and significant improvement was reported by 76.7% patients in prostamol Uno group vs 23.3% in the watchful waiting group. There were no severe side effects. In prostamol Uno group one patient (3.3%) had moderate dyspepsia that resolved without termination of the drug administration. Prostamol Uno showed good efficacy and safety profile in patients with category III prostatitis.