This nationwide population-based retrospective cohort study evaluated the risk of developing prostate cancer among patients with gonorrhea. We identified cases of newly diagnosed gonorrhea in men between 2000 and 2010 from the Taiwan National Health Insurance Research Database. Each patient with gonorrhea was matched to four controls, based on age and index year. All subjects were followed up from the index date to December 31, 2010. The Cox proportional hazards regression model was used to assess the risk of prostate cancer. A total of 355 men were included in the study group, and 1,420 age-matched subjects without gonorrhea were included in the control group. After adjusting for age, comorbidities, urbanization level, hospital level, and monthly income, gonorrhea was significantly associated with an increased risk of prostate cancer (adjusted hazard ratio = 5.66, 95% confidence interval = 1.36-23.52). Men aged 45-70 years and those with lower monthly income were more strongly associated with prostate cancer in the study group than the control group. The higher risk for developing prostate cancer were also found in those without syphilis, without genital warts, without diabetes mellitus, without chronic obstructive pulmonary disease, without benign prostatic hypertrophy, without chronic prostatitis, and without alcoholism. The Kaplan-Meier analysis showed the risk of prostate cancer was significantly higher in the study group than in the control group. Gonorrhea may be involved in the development of prostate cancer. More intensive screening and prevention interventions for prostate cancer should be recommended in men with gonorrhea.