Yohimbine is a presynaptic alpha-2 receptor blocker that decreases outflow of blood from the corporeal tissue. It also probably works on upper levels in the brain to increase libido with its dopaminergic and anti-serotoninergic effect. Isoxsuprine is a beta-adrenergic recepter stimulant that has been effective in arteriogenic impotence with its musculotropic vasodilation effect in some studies. The physiology of erection indicates the necessity of beta-adrenergic stimulation and alpha-adrenergic blockade, so that the combination of yohimbine and isoxsuprine is sometimes effective in patients refractory to one or the other. Trazodone is antidepressant with little anticholinergic effect and results in erection when injected directly into the corpus cavernosum. It has been proved to be useful sometimes in conjunction with other oral medications. We assessed the effect of combination therapy of yohimbine + trazodone/yohimbine + isoxsuprine in 41 impotent patients who wanted non-invasive treatment and compared meen age, penobrachial index and serum testosterone level between the responders and non-responders. 1. For 18 psychogenic impotent patients, yohimbine 10mg+trazodone 25mg 3 times a day were given orally for 2 weeks. Among the 13 cases who were followed-up, none showed complete response, 7 partial responses and 6 no responses. 2. For 7 psychogenic and 16 arteriogenic impotent patients, yohimbine 10mg+isoxsuprine 10mg 3 time a day were given orally for 2 weeks. Among the 5 psychogenic impotent patients who were follow-up, nono showed complete response, 1 partial response and 4 no responses. Out of 8 arteriogenic impotent patients who were followed-up, nono showed complete response, 3 partial responses and 5 no responses. 3. There were no significant difference mean ages, mean PBI and serum testosterone level between responders and non-responders. Therefore there was no significant effect of yohimbine 10mg+isoxsuprine 10mg/yohimbine 10mg+trazodone 25mg tid a day for 2 weeks on the recovery of potency in psychogenic and/or arteriogenic impotent patients.