In three patients with cat scratch disease the liver was affected. All three had high fever (39 degrees C) for more than 3 weeks. Two of them had no peripheral adenopathy. Computed tomography of the abdomen revealed focal hepatic defects in two patients and periportal and periaortic adenopathy in the third. At laparotomy, there were nodules on the liver surfaces of all patients and histological examination revealed necrotising granulomata. The Warthin-Starry silver stain showed organisms consistent in appearance with the cat scratch bacillus in the liver and a periaortic lymph node of one patient, in the liver of the second patient, and in the axillary lymph node of the third. In all three patients the clinical findings and radiological abnormalities improved without specific therapy. A review of the surgical pathology files of Washington University revealed only two other cases of granulomatous hepatitis in children over a 6-year period. These findings indicate that cat scratch disease should now be included in the differential diagnosis of granulomatous hepatitis, at least in children. The absence of peripheral adenopathy in two of the three patients with granulomatous hepatitis suggests that the clinical spectrum of cat scratch disease may be broader than previously appreciated.