Hepatic steatosis is common in patients with chronic hepatitis C (CHC) and is reported to be a risk factor for progression of fibrosis. The aims of this study were to evaluate the interactions between hepatic steatosis and fibrosis in a well-defined cohort of patients with CHC. The computerized pathology database at the National Institutes of Health Clinical Center was searched for patients with CHC who had undergone liver biopsy between 1980 and 2003. Biopsies were scored for necroinflammation using a modified histology activity index, fibrosis using the Ishak system, and steatosis as either none (<5% of cells), mild (5%-25%), or moderate-to-severe (>25%). Four hundred ninety-four patients were identified. The mean age was 44 +/- 9.8 years; 60% were male, 80% Caucasian, and 65% were infected with genotype 1. Steatosis was mild in 31% and moderate to severe in 9% of patients. In univariate analysis, steatosis was associated with increased age, body weight, body mass index (BMI), alanine aminotransferase (ALT) levels, histological necroinflammatory activity, and fibrosis. However, in multivariate analysis, steatosis was associated only with increased age, BMI, and ALT levels and not with fibrosis. One hundred thirty-six patients had 2 liver biopsies separated by 0.5 to 17 years. Worsening of fibrosis occurred in 40% of patients and correlated independently with increasing age, periportal necroinflammation, and ALT elevations but not with steatosis. In conclusion, in this cohort of patients with CHC, steatosis was associated with older age, higher BMI, and higher serum ALT levels but not with the presence of or subsequent progression of fibrosis.