Hepatitis C virus (HCV) infection recurs in liver recipients who are viremic at transplantation. We conducted a randomized, controlled trial to test the efficacy and safety of pretransplant pegylated interferon alpha-2b plus ribavirin (Peg-IFN-α2b/RBV) for prevention of post-transplant HCV recurrence. Enrollees had HCV and were listed for liver transplantation, with either potential living donors or Model for End-Stage Liver Disease upgrade for hepatocellular carcinoma. Patients with HCV genotypes (G) 1/4/6 (n = 44/2/1) were randomized 2:1 to treatment (n = 31) or untreated control (n = 16); HCV G2/3 (n=32) were assigned to treatment. Overall, 59 were treated and 20 were not. Peg-IFN-α2b, starting at 0.75 μg/kg/week, and RBV, starting at 600 mg/day, were escalated as tolerated. Patients assigned to treatment versus control had similar baseline characteristics. Combined virologic response (CVR) included pretransplant sustained virologic response and post-transplant virologic response (pTVR), defined as undetectable HCV RNA 12 weeks after end of treatment or transplant, respectively. In intent-to-treat analyses, 12 (19%) assigned to treatment and 1 (6%) assigned to control achieved CVR (P = 0.29); per-protocol values were 13 (22%) and 0 (0%) (P = 0.03). Among treated G1/4/6 patients, 23 of 30 received transplant, of whom 22% had pTVR; among treated G2/3 patients 21 of 29 received transplant, of whom 29% had pTVR. pTVR was 0%, 18%, and 50% in patients treated for <8, 8-16, and >16 weeks, respectively (P = 0.01). Serious adverse events (SAEs) occurred with similar frequency in treated versus untreated patients (68% versus 55%; P = 0.30), but the number of SAEs per patient was higher in the treated group (2.7 versus 1.3; P = 0.003).