To evaluate the efficacy and safety of a new serotonergic centrally acting drug tramadol in delaying ejaculation in patients with premature ejaculation. Sixty-four potent men with premature ejaculation were randomly assigned to receive 50 mg tramadol (group 1, n = 32) or placebo (group 2, n = 32) approximately 2 hours before planned sexual activity, for 8 weeks. Pretreatment evaluation included history and physical examination, intravaginal ejaculatory latency time, International Index of Erectile Function, and Meares-Stamey test. The efficacy of 2 treatments was assessed using responses to International Index of Erectile Function, intravaginal ejaculatory latency time evaluation, and several general assessment questions. Fifty-seven (89%) completed the whole treatment schedule. The mean intravaginal ejaculatory latency time after tramadol and placebo increased from 19 and 21 seconds to approximately 243 and 34 seconds, respectively (P < 0.001). The mean weekly intercourse episodes increased from pretreatment values of 1.07 and 1.1 to 2.3 and 1.3, for tramadol and placebo, respectively (P < 0.05). Baseline mean intercourse satisfaction domain values of International Index of Erectile Function 10 and 11 reached to 14 and 10 at 8-week treatment in groups 1 and 2, respectively (P < 0.05). There was no withdrawal caused by adverse effects with tramadol or placebo, but more adverse events were associated with tramadol treatment (P < 0.05). Tramadol seems to provide significantly better results in terms of intravaginal ejaculatory latency time and intercourse satisfaction versus placebo. Further studies are required to draw final conclusions on the efficacy of this drug in premature ejaculation.