Objective To evaluate the efficacy and safety of tadalafil in Asian men with both lower urinary tract symptoms associated with benign prostatic hyperplasia and erectile dysfunction. Methods The present phase 3, randomized, double-blind, parallel, placebo- and tamsulosin-controlled study was carried out at 40 study centers in the Asia-Pacific region (mainland China, Taiwan and Korea; NCT01937871). Participants were randomized to receive a placebo (n = 361), tadalafil 5 mg (n = 362) or tamsulosin 0.2 mg (n = 185) in a 2:2:1 ratio for 12 weeks. Results A total of 909 Asian men were randomized into three groups. After 12 weeks of treatment, a statistically significant improvement in least squares mean change from baseline in total International Prostate Symptom Score was observed in the tadalafil versus the placebo group (-5.49 vs -4.08, respectively; P < 0.001). A statistically significant improvement in the change from baseline for the International Index of Erectile Function-Erectile Function domain score, was observed in tadalafil compared with the placebo at 12 weeks (5.24 vs 1.88, respectively; P < 0.001). A significant improvement was observed in the change from baseline in the percentage of "Yes" responses to Sexual Encounter Profile questions 2 and 3 in the tadalafil versus placebo group at 12 weeks (23.87% vs 10.90%; P vs 15.96%; P < 0.001, respectively). Safety results were consistent with the known tadalafil safety profile. Conclusions Tadalafil is efficacious and well tolerated in the treatment of Asian men with both lower urinary tract symptoms associated with benign prostatic hyperplasia and erectile dysfunction.