Autopsy and liver biopsy specimens from 30 pediatric patients with acquired immune deficiency syndrome (AIDS) or AIDS-related complex (ARC) were retrospectively reviewed. Of 28 cases with histologic abnormalities, the following findings were noted singly or in combination: giant-cell transformation, cytomegalovirus inclusions, Kaposi's sarcoma, diffuse lymphoplasmocytic infiltrate, granulomatous hepatitis, mild portal inflammation, necrosis around central veins, steatosis, and cholestasis. For the most part, abnormalities in the liver were not predictive of those in other organs, but the two children with the diffuse parenchymal lymphoplasmocytic infiltrate also had lymphoid interstitial pneumonitis (LIP). Liver histopathology in pediatric patients with AIDS shares some features with that in adults, but appreciable differences are noted. In particular, these differences include the higher frequency of giant-cell transformation and the lower frequency of granulomas in children and the observation of diffuse lymphoplasmocytic infiltrate associated with LIP.