Four patients with liver abscesses and Crohn's disease are described, and reports of 14 cases in the English language literature are reviewed. The incidence of liver abscess in patients with Crohn's disease (114-297 per 100,000) appears to be higher than that of liver abscess in the general population (8-16 per 100,000). Frequently the clinical manifestations of liver abscess are mistaken for a reactivation of Crohn's disease, and diagnosis is delayed. In comparison to patients with liver abscess in the general population, patients with Crohn's disease and liver abscess are considerably younger, are more likely to have multiple rather than solitary abscesses, and usually have a predisposing intraabdominal focus of infection, rather than a biliary one. Streptococci, especially Streptococcus milleri, are the most frequent cause of liver abscess in patients with Crohn's disease. Liver scanning should be performed routinely in patients with Crohn's disease in whom a febrile illness cannot be completely explained by bowel disease, or in whom fever does not respond to drainage of intraabdominal abscesses.