ObjectiveTo explore risk factors of infectious complications following transrectal ultrasound-guided prostate biopsy (TRUSPB).MethodsWe retrospectively analyzed 1,203 patients with suspected prostate cancer who underwent TRUSPB at our center between December 2012 and December 2016. Demographics, clinical characteristics, and data regarding complications were collected, and then univariate and multivariate logistic regression analyses were used to identify independent risk factors for infectious complications after prostate biopsy.ResultsMultivariate logistic analysis demonstrated that body mass index (BMI) (OR=2.339, 95% CI 2.029–2.697, P<0.001), history of diabetes (OR=2.203, 95% CI 1.090–4.455, P=0.028), and preoperative catheterization (OR=2.303, 95% CI 1.119–4.737, P=0.023) were risk factors for infection after prostate biopsy. The area under the receiver operating characteristics curve for infectious complications was 0.930 (95% CI 0.907–0.953, P<0.001). BMI=28.196 kg/m2 was the best cut-off threshold for predicting infection after TRUSPB.ConclusionBMI >28.196 kg/m2, history of diabetes, and preoperative catheterization are independent risk factors for infection after prostate biopsy.