Hepatic steatosis is common in hepatitis C virus (HCV)-infected patients and may be associated with the metabolic syndrome. We studied steatosis in patients treated with peginterferonalpha-2a plus ribavirin. Forty-five of 207 patients (22%) had >5% hepatic steatosis at baseline. Significantly more patients with steatosis than without were HCV genotype 3 (51%vs 14%; P < 0.0001) had higher HCV-RNA (P = 0.0045), body weight (P = 0.0176), body mass index (BMI, P = 0.0352) and serum triglycerides (TG) (P = 0.0364), hypertriglyceridaemia (P = 0.0009), elevated blood pressure/history of hypertension (P = 0.0229) and lower cholesterol (P = 0.0009). Significant steatosis predictors were genotype 3 (OR 9.04, 95% CI 3.85-21.21, P < 0.0001), HCV-RNA (OR 2.96, 1.49-5.88, P = 0.0019) and triglycerides (OR 1.06, 1.02-1.11, P = 0.0071). In genotype 3 patients, HCV-RNA was the only significant predictor (OR 11.15, 2.60-47.81, P = 0.0012). In non-genotype 3 patients, hypertriglyceridaemia was the only significant predictor (OR 1.07, 1.02-1.12, P = 0.0041). 134 of 207 patients (65%) achieved an sustained virological response (SVR) with peginterferon alpha-2a plus ribavirin, similar to the overall response rate. In genotype 3 patients with an SVR, steatosis decreased from 48% to 13% (baseline to end-point). No change was seen in the steatosis rate in non-genotype 3 patients with an SVR. This large and comprehensive analysis of a large data base from a multinational trial further adds to the observations that chronic HCV is associated with hepatic steatosis in approximately a fifth of patients. Further, features of the metabolic syndrome are associated with hepatic steatosis in most of these patients. Steatosis is significantly more common in genotype 3 compared with other genotypes, and in these patients, an SVR is associated with steatosis clearance.