The use of herbal medications is increasing significantly in the UK and there is a perception that herbal preparations are without adverse effects. This case report highlights the potential risks of black cohosh, which is one of the most commonly used herbal products. This is a case report of a 60-year-old Caucasian lady who presented with subacute liver failure secondary to taking black cohosh. This was further confirmed by liver biopsy and she subsequently deteriorated and underwent liver transplantation. Available evidence supports an association between black cohosh and risk of hepatotoxicity. In current literature, there have only been four previously reported cases of hepatotoxicity associated with black cohosh, which required liver transplantation. We submit that our patient represents the fifth case. We recommend that patients taking this supplement should have close monitoring of their hepatic function, especially in the presence of other risk factors.