Objective: To explore the clinical features, biopsy results and risk factors of patients underwent prostate biopsy with age≤55, and to help make the proper treatment strategies of this cohort of patients. Methods: The data of patients with age≤55 underwent prostate biopsy between Jan 2011 and Nov 2013 was retrospectively reviewed. Clinical factors including prostate-specific antigen, digital rectal examination, ultrasonography and magnetic resonance imaging were recorded. Biopsy positive results were defined as the presence of prostate cancer and high-grade prostate cancer (Gleason score≥7). Results: There were all together 82 patients in this cohort, with the median age of 51 years old and median prostate-specific antigen of 8.62 μg/L. Among them 71 patients (86.6%) underwent pre-biopsy magnetic resonance imaging test, with 25 positive (35.2%), 18 suspicious (25.4%) and 28 negative results (39.4%). Pathology confirmed prostate cancer in 26 patients (31.7%), including 23 (28.0%) high-grade prostate cancer. Higher prostate-specific antigen, positive ultrasonography and positive magnetic resonance imaging were risk factors for prostate cancer and high-grade prostate cancer. For patients with prostate-specific antigen between 4 and 10 μg/L, 15.0% were diagnosed with prostate cancer, and positive ultrasound and magnetic resonance imaging were predictive for biopsy results. Conclusions: The positive rate of prostate biopsy in men younger than 55 years old is 31.7%, and the risk for prostate cancer of this cohort of patients shouldn't be neglected. Prostate-specific antigen value, ultrasonography and magnetic resonance imaging could help predict biopsy results.