To assess extent of hepatic involvement in measles, we evaluated prospectively 144 patients (ages 0.2 to 43 years) during an outbreak. Liver function parameters (AST, ALT, serum gamma-glutamyl transpeptidase and bilirubin) were determined on presentation and at 2 and 4 weeks. The study comprised 52 pediatric (less than or equal to 14 years) and 92 adult patients. Liver dysfunction was evident quite often (56 to 66%) in adult patients. However, in the pediatric age group, these abnormalities were less frequent and less extensive. Moreover, a significant correlation was noted between age and each of the following parameters: AST (r = 0.61), ALT (r = 0.56) and serum gamma-glutamyl transpeptidase (r = 0.39). In all subjects all parameters normalized after 2 to 4 weeks. The data presented suggest that hepatic dysfunction in measles is probably not rare and is more frequent and more extensive in adults. However, these abnormalities seem to be subclinical, self-limited and probably with no long-term sequelae.