The eosinophilia-myalgia syndrome associated with L-tryptophan-containing products is highlighted by eosinophilia, incapacitating myalgias, and diverse multisystemic manifestations. In addition to involvement of the skin, skeletal muscle, and peripheral nerves, visceral damage has been quite prominent, particularly affecting the lungs, the heart, and the liver. Hepatic involvement has been manifested by altered liver tests but is clinically silent. We report the unique case of a woman with this syndrome who developed abdominal pain, a clinical picture of hepatitis and chronically abnormal liver tests. Histologic examination of the liver disclosed eosinophilic hepatitis with piecemeal necrosis. The occurrence of clinically overt hepatic involvement has not been reported previously. Potential mechanisms of liver damage in eosinophilia-myalgia syndromes are discussed.