A new study could not find a difference in erectile function 1 year after prostatectomy in men taking sildenafil either on demand or nightly. The 100 preoperatively potent men (<65 years in age) underwent nerve-sparing minimally invasive radical prostatectomy, and had similar international index of erectile function (IIEF) scores at baseline (before prostatectomy) and throughout the 13-month follow-up period. No differences in other relevant measures, including attempted intercourse frequency and confidence, could be determined.