The relationship between sexually transmitted infections (STIs) and prostate cancer (PC) remains inconclusive. Moreover, all such studies to date have been conducted in Western populations. This study aimed to investigate the risk of PC following STI using a population-based matched-cohort design in Taiwan. The study cohort comprised 1055 patients with STIs, and 10 550 randomly selected subjects were used as a comparison cohort. Cox proportional hazards regression analysis revealed that the hazard ratio for PC during the 5-year follow-up period for patients with a STI was 1.95 (95% confidence interval 1.18-3.23), that of comparison subjects after adjusting for urbanization level, geographical region, monthly income, hypertension, diabetes, hyperlipidaemia, obesity, chronic prostatitis, history of vasectomy, tobacco use disorder, and alcohol abuse. We concluded that the risk of PC was higher for men who were diagnosed with a STI in an Asian population.