Acute liver failure (ALF) is the product of a rapid, overwhelming insult to the liver that destroys parenchymal function, resulting in a multisystem illness characterized by coagulopathy and encephalopathy. Viral infections and drug induced liver injury are the most common causes of ALF.1 The most common viral precipitants are the hepatotropic viruses, hepatitis A, B and E (ALF due to hepatitis C is rare outwith the context of liver transplantation). Defective cell-mediated immunity is associated with increased susceptibility to viral hepatitis; reactivation of hepatitis B may occur in those receiving chemotherapy or immunosuppression2 while hepatitis E follows a more severe course in pregnant women and is reported to cause chronic hepatitis in organ transplant recipients.3 Systemic viral infections such as herpes viruses (Epstein–Barr virus, cytomegalovirus, herpes simplex), parvovirus and adenovirus can also affect the liver. In immunocompetent hosts they usually cause a mild collateral hepatitis, but in immunosuppressed individuals, impaired immune surveillance may result in secondary visceral infection, which if severe, may precipitate ALF.4 We describe two fatal cases of ALF due to opportunistic non-hepatotropic viral infections in adult solid organ transplant recipients. A 46-year-old female cardiac transplant recipient was admitted with fever and dyspnoea. She had received a heart transplant 10 months earlier for complications of congenital heart disease and was receiving mycophenolate mofetil (MMF) and cyclosporine immunosuppression. While there was no obvious site of infection, she was commenced on broad spectrum antibiotics following a full sepsis screen (which included bacterial cultures and viral serology), and her immunosuppression was reduced. Liver enzymes were mildly deranged at the time of admission with an ALT of 57 IU/l. Her condition deteriorated over the following 48 h with the development of severe hepatitis (ALT 1919 IU/l and INR 1.4) and renal impairment, which prompted her transfer to the …