In industrialized countries, over-the-counter dietary supplements have become popular in preventing and treating an expanding list of medical conditions. Although most commercially available supplements have not been rigorously tested for safety and efficacy, they have found an enlarging market because they are considered natural. Oral supplements containing green tea extract have been marketed as effective for weight loss and to prevent and cure some solid tumors. Although there is little scientific evidence of the effectiveness of green tea extracts to improve the quality of health of regular consumers, there is an increasing body of medical literature supporting the hypothesis that they can cause serious side effects. Our experience adds to previous reports of acute liver toxicity observed in individuals consuming supplements containing green tea extract. We highlight the importance of obtaining a detailed history of dietary supplement consumption when evaluating a patient presenting with acute liver dysfunction.