Transrectal ultrasound (TRUS)-guided biopsy remains the mainstay of the diagnosis of prostate cancer. Although this diagnostic method is a safe procedure and well tolerated by most patients a significant number of patients report discomfort and pain during prostate biopsy. In order to define the best method of anesthesia, many studies, in which different methods were compared, have been performed. To determine the effectiveness of local injection anesthesia in TRUS-guided prostate biopsy, we designed and performed this prospective study in order to evaluate the utility of periprostatic nerve block for pain management. A total of 100 patients who had elevated total prostate-specific antigen (tPSA) and/or abnormal digital rectal examination (DRE) were included in this study. Half of the patients received periprostatic injection anesthesia (group I) and the remaining half received placebo (group II). Patients received 10 cm(3) (5 cm(3) each side) 1% lidocaine injected into the periprostatic nerve plexus under transrectal ultrasonic guidance. Pain during biopsy was assessed using a 10-point modified visual analog scale WAS). In groups I and II, mean patient age was 66.8+2.5 and 65.6+11.5y, mean tPSA was 7.87+/-3.6 and 11.3+/-1.7 ng/ml, mean biopsy duration was 6.5 +/- 2.5 and 6.6 +/- 2.2 min and mean pain score during TRUS-guided biopsy was 1.46 +/- 2.2 and 4.5 +/- 2.1, respectively. No statistically significant difference was observed with respect to age, tPSA and mean biopsy duration between these groups. Mean pain VAS score was statistically or significantly better (P = 0.0001) in the lidocaine injection group (group I), and furthermore no patient had a VAS pain score greater than or equal to5 in this group. Only minor and transient complications occurred in both groups. This study reinforces the usage of periprostatic nerve block as a standard method of pain management during TRUS-guided prostate biopsy, because it is simple, safe, uncostly and significantly effective without requiring additional time.