Herbal hepatotoxicity is increasingly recognized as herbal medicines become more popular in industrialized societies. Some herbal products may potentially benefit people with liver disease; however, these benefits remain generally unproved in humans, and a greater awareness of potential adverse effects is required. Herbal use is often not disclosed, and this may result in a diagnostic delay and perpetuation or exacerbation of liver injury. Female gender may predispose to hepatotoxicity, and concomitant agents that induce cytochrome P450 enzymes may also increase individual susceptibility. The range of liver injury includes minor transaminase elevations, acute and chronic hepatitis, steatosis, cholestasis, zonal or diffuse hepatic necrosis, hepatic fibrosis and cirrhosis, veno-occlusive disease, and acute liver failure requiring transplantation. In addition to the potential for hepatotoxicity, drug-drug interactions between herbal medicines and conventional agents may affect the efficacy and safety of concurrent medical therapy. This review focuses on emerging hepatotoxins and patterns of liver injury, potential risk factors for herbal hepatotoxicity, and herb-drug interactions. Appropriate reporting and regulatory systems to monitor herbal toxicity are required, in conjunction with ongoing scientific evaluation of the potential benefits of phytotherapy.