BACKGROUND: Catheter-related bladder discomfort (CRBD) secondary to catheterization of urinary bladder is distressing. In the present study, we evaluated gabapentin for preventing CRBD. METHODS: One-hundred and eight consecutive adult patients, ASA physical status I and II, of either sex, undergoing elective percutaneous nephrolithotomy were randomized into two groups of 54 each. Group control: placebo and group G gabapentin: gabapentin 600 mg. Drugs were administered orally 1 h before surgery. After induction of anesthesia, patients were catheterized with a 16F Foley catheter and the balloon was inflated with 10 mL normal saline. In the postanesthesia care unit, the incidence and severity (mild, moderate, and severe) of CRBD were assessed on arrival (0) and at 1, 2, and 6 h. RESULTS: Gabapentin reduced the incidence of CRBD to 50% (27 of 54) compared with 80% (43 of 54) observed in the control group (P < 0.05). Gabapentin also reduced the severity of CRBD and postoperative pain as observed by a reduction in the number of patients requiring any fentanyl and the total fentanyl consumption postoperatively (P < 0.05). CONCLUSION: Gabapentin (600 mg) administered orally 1 h before surgery reduced the incidence and severity of CRBD, postoperative pain, number of patients requiring fentanyl and postoperative total fentanyl requirement.