The chronological distribution of sexual intercourses in a group of patients treated with tadalafil versus placebo for 3 months was evaluated. In total, 120 patients with ED were randomized in two groups and treated, respectively, with one pill of tadalafil 20 mg or placebo on Tuesday and on Friday. After 3 months, we collected data using IIEF and SEP diaries. After 3 months, IIEF score and percentages of success SEP diaries increased in the tadalafil group (<0.01) versus placebo group. Considering all the successful intercourses of the 3 months of tadalafil assumption, the highest percentages were reported within 6-12 h range (35%) and 12-24 h range (28%). In tadalafil group, 41% of patients reported their first successful intercourse between 1 and 6 h and 78% of patients reported the recovery of spontaneous erections. In conclusion, after carrying out the first sexual attempt between 1 and 6 h, patients engaged in sexual activity between 6 and 24 h.