Although acute liver failure due to the varicella-zoster virus is rare, it is frequently fatal. Immunologic impairment is a significant predisposing factor. Classic symptoms at presentation are rash, abdominal pain, and fever. After some days patients go on to develop full-blown liver failure. The diagnosis can be confirmed by histological examination and electron microscopy with fluorescent staining, immunohistochemistry, and in situ hybridization of the liver. In cases of high suspicion, acyclovir therapy should not be delayed.