BACKGROUND: There is significant histologic and biochemical overlap between nonalcoholic fatty liver disease (NAFLD) and steatohepatitis associated with choline deficiency. OBJECTIVE: We sought to determine whether subjects with biopsy-proven NAFLD and evidence of an inadequate intake of choline had more severe histologic features. DESIGN: We performed a cross-sectional analysis of 664 subjects enrolled in the multicenter, prospective Nonalcoholic Steatohepatitis Clinical Research Network (NASH CRN) with baseline data on diet composition (from a recall-based food-frequency questionnaire) within 6 mo of a liver biopsy. Food questionnaires were analyzed with proprietary software to estimate daily intakes of choline. Liver biopsies were centrally read, and consensus was scored with the NASH CRN-developed scoring system. Because choline needs vary by age, sex, and menopausal status, participants were segregated into corresponding categories (children 9-13 y old, males ≥14 y old, premenopausal women ≥19 y old, and postmenopausal women) on the basis of the Institute of Medicine's definition of adequate intake (AI) for choline. Deficient intake was defined as <50% AI. RESULTS: Postmenopausal women with deficient choline intake had worse fibrosis (P = 0.002) once factors associated with NAFLD (age, race-ethnicity, obesity, elevated triglycerides, diabetes, alcohol use, and steroid use) were considered in multiple ordinal logistic regression models. Choline intake was not identified as a contributor to disease severity in children, men, or premenopausal women. CONCLUSION: Decreased choline intake is significantly associated with increased fibrosis in postmenopausal women with NAFLD. The Pioglitazone vs Vitamin E vs Placebo for Treatment of Non-Diabetic Patients With Nonalcoholic Steatohepatitis trial was registered at clinicaltrials.gov as NCT00063622, and the Treatment of Nonalcoholic Fatty Liver Disease in Children trial was registered at clinicaltrials.gov as NCT00063635.