BACKGROUND Pruritus is a common and bothersome problem in 30-50% of hemodialysis patients. The aim of this study was to determine the effect of gabapentin, 100 mg/three times a week (after each hemodialysis session), on uremic pruritus. METHODS Patients older than 18 years who had undergone hemodialysis for more than three months were enrolled in this double-blind clinical trial. They had experienced pruritus refractory to antihistamines for at least two weeks. The patients were assigned to receive gabapentin 100 mg following hemodialysis for a period of four weeks, and after a washout week, they received the placebo for another four weeks. They were asked to evaluate the severity of their pruritus using a visual analogue scale (VAS). The reduction of pruritus >or= 50% was accepted as the response. RESULTS The mean pruritus score reached 6.44 +/- 8.4 (p < 0.0001), 15 +/- 11.2 (p < 0.001), and 81.11 +/- 11.07 (p < 0.001) during gabapentin, washout, and placebo periods, respectively. No significant correlation was found between age, sex, duration of dialysis, underlying diseases, and systolic and diastolic blood pressures and the gabapentin effect. CONCLUSIONS Gabapentin is an effective agent in treating uremic pruritus.