The therapeutic efficacy and tolerance of a new 150,000 U (40 mg) formulation of mepartricin (to be administered once-a-day in the evening) were evaluated during a double-blind study against placebo in 2 groups of uncomplicated BPH patients treated for 60 days. The data obtained disclosed a positive pharmaco-therapeutic effect of this new formulation coupled with excellent local and systemic tolerance. At the end of trial the various objective and subjective parameters considered showed marked improvement in the group treated with mepartricin, with statistically significant differences from the placebo-treated group. The treatment efficacy was judged positive in 74-78% of cases by patients and physicians in the mepartricin group and in 36.4% of cases in the placebo group.