The aim of this study was to determine if a relationship exists between nonalcoholic steatohepatitis (NASH) and serum levels of free fatty acids, choline deficiency, or celiac disease. Forty-seven patients with liver biopsy proven NASH were enrolled. Total serum free fatty acids and anti-endomysial antibodies were determined in all patients, while plasma free and phospholipid-bound choline were determined in 29 patients. Total serum free fatty acid concentration correlated significantly with female gender and serum albumin concentration. Patients with severe fibrosis on liver biopsy had significantly greater serum concentration of free fatty acids than patients without severe fibrosis. Plasma free and phospholipid-bound choline levels were normal and no significant correlation was found between the concentration of plasma free or phospholipid bound choline, and the severity of liver damage. Only one of the 47 patients with NASH had a positive titer for the anti-endomysial antibody. In conclusion, increased serum concentrations of free fatty acids were found in NASH and were associated with development of more severe liver disease. Neither choline deficiency nor celiac sprue by anti-endomysial antibody testing was associated with NASH.