Objective: High prevalence of erectile dysfunction(ED)was observed in patients with chronic prostatitis/chronic pelvic pain syndrome(CP/CPPS).However,it is still unknown whether CP/CPPS is a risk factor of ED.This systematic review and meta-analysis was conducted to evaluate the relationship between CP/CPPS and ED.Methods: PubMed,EMBASE,Web of Science and the Cochrane library were searched up to November 2014 to identify literatures that reported the association between CP/CPPS and ED.Case-control,cohort or crosssectional studies were included.Newcastle-Ottawa Quality Assessment scale was used in assessing qualities of included case-control and cohort studies and an eleven item quality assessment table was used in cross-sectional studies.This meta-analysis was conducted according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses statement.Odds ratio of ED and mean difference of 5-item International Index of Erectile Function scores were pooled across studies and analyzed using random effect model.Results: A total of 3 cross-sectional studies,2 case-control studies and 4 retrospective studies with 31,956 participants were included to calculate pooled OR of ED,and 2 studies for pooled mean difference of IIEF-5 score.A strong correlation between CP/CPPS and ED(pooled OR: 3.02,95%CI: 2.18-4.17,P<0.01)was found,with significant heterogeneity across studies(I2=65%,P<0.01).Also a significant decrease of IIFE-5 score in CP/CPPS group(pooled MD:-4.54,95%CI:-5.11--3.98,P<0.01)was observed.Conclusions: Patients with CP/CPPS have a more increased risk of suffering from ED,but the mechanisms were unclear.Evidence of higher level is needed to further confirm this relationship.Physicians should pay more attention on erectile function of patients with CP/CPPS.