We present the first case report in the UK of acute liver failure caused by efavirenz therapy culminating in liver transplantation. A 26-year-old Zimbabwean woman commenced emtricitabine, tenofovir and efavirenz (Atripla) in December 2011. Her liver function tests at baseline and at 20 days after initiating antiretroviral therapy were normal. At three months of therapy her blood tests haemolysed and were not processed. She had previously missed follow-up appointments and on this occasion failed to return for repeat tests. She was not seen again until after six months of antiretroviral therapy when she presented to her general practitioner with acute liver failure. Her condition deteriorated and she required liver transplantation. She recovered well and re-started antiretroviral therapy to good effect. The case illustrates the value of routine monitoring after initiating antiretroviral therapy and the fundamental importance of engaging patients in long-term management to ensure safe treatment.