We present 3 cases of immunocompetent infants with CMV infection who showed prolonged liver dysfunction. In all cases the CMV genome was detectable in hepatocytes using the in situ hybridization method. Combination therapy with ganciclovir (GCV) and hyperimmune gammaglobulin (HGG) was instituted in 2 cases and successfully suppressed the replication of CMV, with sustained improvement in liver function. In 1 of these cases, signals for CMV DNA were undetectable in the liver 12 months after termination of combination therapy. These results help to confirm the etiology of CMV for persistent hepatitis in immunocompetent infants using the in situ hybridization method and also show the efficacy of combination therapy with a virostatic agent, GCV, and an immune-modulating agent, HGG.