Background: Drug-induced liver injury (DILI) is the most common cause of acute liver failure in the Western world. While it requires a diagnosis of exclusion, it is exceedingly prevalent in patients taking multiple hepatotoxic agents, the foremost of which are antibiotics, followed by herbal and dietary supplements. Below we will discuss a case of nafcillin-induced liver injury suggested by a thorough work-up and rule-out of other hepatic and biliary pathologies.