Trials of the efficacy and safety of vardenafil in the treatment of male erectile dysfunction (ED) were meta-analysed. All available databases were searched (January 1, 2001-November 30, 2003). Trials were eligible if they included men with ED, compared vardenafil with placebo, were randomized, were at least of 12 weeks duration, and assessed clinically relevant outcomes. Two reviewers independently evaluated study quality and extracted data in a standardized fashion. Nine trials (6809 men) met the inclusion criteria. In results pooled from seven fixed-dose trials, vardenafil increases the Erectile Function domain of the International Index of Erectile Function questionnaire by 6.18 units (weighted mean difference (WMD)). Vardenafil also increases the percentage of erections firm enough to allow vaginal penetration (WMD: 26) and the percentage of sexual attempts that were successful per participant (WMD: 29.8). The percentage of men agreeing with the statement that 'the treatment they have been taking over the past 4 weeks improved their erections', is also in favour of vardenafil (relative risk (RR): 3). These efficacy variables appeared greater at higher doses, although there are no significant differences between 10 and 20 mg dose. The same results were extracted for the two flexible 'as needed' dosing trials. Discontinuations are greater at the vardenafil groups compared to placebo (RR: 2.25). Specific adverse events with vardenafil included flushing, dyspepsia, headache, and rhinitis. Vardenafil was not significantly associated with serious cardiovascular events or death. Vardenafil, in all treatment regimens, shows to possess superior efficacy to placebo in the treatment of patients with erectile dysfunction. More data is needed on patients' subgroups.