This study assessed the effect of 10mg vardenafil, taken on demand in an 'at home' setting, as compared to placebo (dummy medication with no pharmacological activity), on the duration of erection from the moment when the patient perceived his erection to be hard enough for penetration until withdrawal from the partner's vagina leading to successful completion which may or may not have included ejaculation. The patient used the stopwatch for the above assessments. The efficacy of oral ED treatments is measured by questionnaires and patient diaries.

Inclusion Criteria:- Males with erectile dysfunction- Stable heterosexual relationship Exclusion Criteria:- Primary hypoactive sexual desire- History of myocardial infarction, stroke or life-threatening arrhythmia within the prior 6 months nitrate use