Hepatic involvement was investigated in 31 children with perinatal HIV-1 infection, who were followed for 2-82 months (mean 30.5). Liver disease, as revealed by increased aminotransferase levels, liver biopsy or necroscopy, was diagnosed in 18 children (58%), of which 7 (22.5%) had acute hepatitis and 11 (35.5%) showed chronic liver disease. Overall, 40 persistently active or recurrent viral infections, as demonstrated by positive culture and/or detection of serum DNA, specific IgM, IgA and high levels of IgG, were revealed in the children with liver disease, while 12 similar infections were detected in 13 children without liver disease (p < 0.001). In particular, the children with liver disease showed a significantly (p < 0.002) higher incidence of cytomegalovirus (CMV) infections than children without liver disease (13 versus 3). Moreover, hepatitis C and B virus infections were revealed only in children with liver disease (5 and 1 patients, respectively). Clinical outcome showed a significantly (p < 0.001) higher mean survival in the children without liver disease than those with liver disease (47.5 versus 18.2 months). In fact, nine of the children with liver disease (50%) died, as opposed to only one of the children without liver disease (7.7%; p = 0.01). Based on these findings, liver disease is indicative of a poor prognosis in children with HIV infection, being related to the presence of multiple active viral infections.