Chronic hepatitis C infection (CH-C) accounts for a significant number of patients undergoing orthotopic liver transplantation (OLT). Recently, hepatitis C virus (HCV) genotype-dependent differences in disease outcome and therapeutic responses have been suggested. The objectives of our study were to determine (1) the recurrence of HCV infection after OLT; (2) distribution of HCV genotypes in patients with CH-C who required liver transplantation compared with those who did not; and (3) the 1-year transplantation outcome in patients infected with different hepatitis C genotypes. RNA was extracted from sera of 20 patients who underwent OLT for end-stage liver disease secondary to CH-C (group I) and 52 patients with CH-C who did not require OLT (group II). For viral RNA detection, reverse transcriptase and polymerase chain reaction (RT/PCR) of 5′U region was performed on all OLT patients both before and after OLT. For genotyping, RT-PCR of the NS 5 region was performed, followed by automated sequencing of the amplification products. Nineteen OLT patients had viral RNA detected by PCR both before and after OLT. One patient had no RNA detected before OLT but became viremic after OLT. The prevalence of HCV genotype 1b was significantly higher in group I patients compared with group II (53% v 23% respectively, P = 01). Examination of outcome at 1 year after OLT showed that 9 of 10 patients with HCV genotype 1b had histological evidence of hepatitis compared with 4 of 9 patients with other genotypes (non-1b) (P = 0.06). However, the number of patients who had one or more episodes of rejection, underwent retransplantation, or died at 1 year after OLT were similar. Recurrence of HCV infection after OLT was shown in all studied patients. Hepatitis C genotype 1b is more prevalent in our patients who underwent transplantation compared with a group with chronic hepatitis C who did not require transplantation (P = 0.01). Patients infected with HCV genotype 1b may have a higher risk of histological hepatitis after transplantation.