Fifty-one patients with chronic erectile dysfunction were selected for this study involving intracavernous self-injection therapy with papaverine or prostaglandin E1 (PGE1). Patients were screened and grouped as follows: pronounced vasculogenic, mild vasculogenic, venous leakage, neurogenic and psychogenic impotence. The duration of follow-up in these 51 patients was from 1.5-30.5 months (average, 11.8 months). The average effective dosage of papaverine and PGE1 was variable among the different groups. This kind of therapy proved to be effective in our preliminary results, which showed that 35 patients (68.6%) were found to be good responders and eight patients (15.7%) were temporary responders. In our detailed questionnaire, answered by all 51 patients, we found 29 patients (56.9%) had increased their frequency of sexual activity, 38 patients (74.5%) had sustained their erection more than they ever had before, and 43 patients (84.3%) had enjoyed sexual orgasm following this pharmacologically assisted erection. Compared with papaverine, PGE1 was found to have fewer complications. None of the patients complained of any discomfort after long-term, self-injection with PGE1. However, two patients (3.9%) had sustained erections and two patients (3.9%) developed palpable fibrotic plaque after papaverine injection in our study.