OBJECTIVE To clarify the efficacy of phosphodiesterase-5 inhibitor (PDE5i) in men with premature ejaculation (PE). METHODS We searched the PubMed, Embase, and Cochrane Library databases to identify all randomized controlled trials and compared results, including intravaginal ejaculation latency time, satisfaction, side effects, and others, after treatment with PDE5i vs placebo, PDE5i vs selective serotonin reuptake inhibitor (SSRI), or combined use of PDE5i with SSRI vs SSRI alone for treating PE. RESULTS The study inclusion criteria were met by 10 studies (10 randomized controlled trials with 3 crossover studies) involving 775 patients. The data synthesized from these studies indicated that the efficacy of PDE5i was better than that of placebo; however, more patients had side effects while taking PDE5i. The efficacy of PDE5i was better than that of SSRIs, and no significant difference was observed in the frequency of side effects. The efficacy of the combined treatment was significantly better than that of SSRI alone; however, more patients had side effects from the combined treatment. The major limitations of this meta-analysis were that there is no universally agreed definition of PE, and the types of medications differed among the studies evaluated. CONCLUSION PDE5i was significantly more effective than a placebo or SSRI for treating PE; however, it had more side effects than placebo. The combined treatment of PDE5i and SSRI had better efficacy but more side effects than the use of SSRI alone. (C) 2015 Elsevier Inc.