Background: Although various local anesthesia techniques have been suggested to decrease pain and discomfort during a transrectal ultrasound (TRUS)-guided prostate biopsy, the best method has not yet been defined. The present prospective, double-blind, randomized study aims to investigate the clinical efficacy of ‘walking’ caudal block compared with an intrarectal lidocaine gel for this procedure. Methods: One hundred patients were randomly assigned to two groups. In the lidocaine gel group, 10 ml of gel containing 2% lidocaine was given intrarectally. In the caudal group, 20 ml 0.1% bupivacaine with 75 g fentanyl was injected. Pain scores, anal sphincter tone and patient satisfaction were evaluated. Results: The pain scores were significantly lower in the caudal group at all stages. Verbal rating scores (scale 1–4) during probe insertion, probe maneuver and biopsies were 1 (0–2), 1 (0–2) and 1 (0–2) vs. 3 (0–5), 2 (1–3) and 4 (2–6), respectively (P value <0.0001 at all stages). The anal sphincter was more relaxed in the caudal group than in the gel group (P value <0.0001 in all categories). Highly satisfied patients were more frequently encountered in the caudal group, 34 (68%) vs. 8 (16%), P<0.0001, and unsatisfied patients were more frequently found in the gel group 1 (2%) vs. 12 (24%); P<0.001. All patients were able to walk without any assistance immediately after the procedures. Conclusion: ‘Walking’ caudal analgesia is an efficacious method for relieving the pain during TRUS-guided prostate biopsies in ambulatory practice.