PURPOSE: Regarding for erectile dysfunction(ED), Sildenafil has produced satisfactory clinical results. However, Some patient discontinue sildenafil treatment for a variety of reasons after successful restoration of erectile function. We investigated the reasons for such discontinuations of sildenafil after restoration of erectile function by sildenafil medication. MATERIALS AND METHODS: After sildenafil medication, one hundred fifty six patients whose score of erectile function domain of the 15-item International Index of Erectile Function(IIEF) increased to 26 or more, were included in this study. Six-months after the first sildenafil prescription, compliance to medication and the reason for discontinuity were reviewed by chart or surveyed by telephone. RESULTS: In 156 successfully treated patients, 54(34.6%) discontinued sildenafil medication. The 2 most common reasons for discontinuation were trouble in the partners' or patients' emotional readiness for restoration of sexual activity after long-term abstinence and fear of possible side effects. CONCLUSIONS: After restoration of erectile function, many patients discontinued the use of sildenafil medication. The reasons for discontinuing the medication were primarily emotional or relationship-oriented issues. The counseling of both partners and education about the effects and side effects of the drugs are recommended to promote the successful recovery of sexual activity.