Objective To analyze the expression of urine exosomal miR-375 in prostate tumors and investigate its clinical utility.Methods A total of 45 patients with PCa,24 with benign prostate hyperplasia (BPH) and 24 healthy individuals were enrolled into this study.Exosomes were isolated from the urine of PCa,BPH and healthy individuals and the total RNA was extracted from the exosomes.The exosomal miR-375 expression was assessed by quantitative real-time PCR and analyzed with the comparative quantification cycle method (2-△△CT).We performed comprehensive biostatistical analyses to explore the clinical value of miR-375 in prostate cancer.Results The urine exosomal miR-375 expression was significantly downregulated in the patients with PCa compared with BPH and the healthy controls (P ＜ 0.01).No statistically significant difference of the urine exosomal miR-375 expression levels between the patients with BPH and healthy individuals was observed (P ＞ 0.05).The urine exosomal miR-375 expression level was also found to be associated with clinical stage and bone metastasis status of the patients with PCa (P ＜0.05),and with the increase of Clinical stage.The expression level of miR-375 decreased.No significant relationship was detected between miR-375 level and the patient's age,gleason score and serum prostate-specific antigen level (P ＞ 0.05).Receiver operator characteristic analyses demonstrated that the urine exosomal miR-375 expression could better differentiate PCa from BPH patients:AUC 0.715 (95％ CI:0.589-0.842) vs PSA AUC 0.632 (95％ CI:0.492-0.771) (P＜0.01).Conclusion The urine exosomal miR-375 could serve as a non-invasive biomarker for the diagnosis of PCa.