OBJECTIVE To evaluate the effect of transperineal template-guided prostate mapping biopsy (TTMB) on urinary, bowel and erectile function. PATIENTS AND METHODS In all, 129 men had TTMB; a median of 56 biopsy cores were obtained per patient. Tamsulosin (0.8 mg daily) was initiated 2 days before TTMB and continued for 2 weeks. The International Prostate Symptom Score (IPSS), Rectal Function Assessment Score (R-FAS), International Index of Erectile Function (IIEF)-6 and the postvoid residual volume (PVR) were assessed at baseline and after 30 days, except for the IPSS, which was also assessed at 7 days. Several variables were evaluated as predictors of TTMB-induced morbidity. RESULTS The mean patient age was 64.7 years with a mean prostate volume of 74.3 mL; 60 men (46.5%) were diagnosed with prostate cancer. After TTMB, 39.4%, 7.1% and 1.6% of patients remained catheter-dependent at 0, 3 and 6 days. The median catheter-dependency was 0, 1, 2 and 3 days for prostate volumes of < 60, 60-90, 90-120 and > 120 mL, respectively. No patient remained catheter- dependent for > 12 days or required a transurethral resection secondary to TTMB. The mean IPSS before TTMB was 10.4, and was 4.6 and 3.8 at 7 and 30 days. At baseline and 30 days the mean PVR was 35 and 40 mL, and the median R-FAS and IIEF scores for patients potent before TTMB were 2.0 and 2.2, and 27.0 and 26.0, respectively. CONCLUSIONS TTMB is a promising procedure for diagnosing prostate cancer. TTMB-related morbidity differs from that of standard TRUS biopsy primarily in the incidence of temporary urinary retention, and is comparable in terms of urinary, bowel and erectile function.