A 54 year old man with well compensated cirrhosis attributed to long term methotrexate therapy of psoriasis developed acute hepatic decompensation after being started on therapy with methoxsalen and ultraviolet light. The latency to onset of symptoms and jaundice was not clearly defined in the report and pretreatment laboratory values were not provided. Drug induced liver injury superimposed upon chronic liver disease or cirrhosis often has a different pattern of clinical presentation, usually defined as "acute-on-chronic". Laboratory values may also be unusual, the only change from baseline abnormalities being a sudden appearance of jaundice followed rapidly by signs and symptoms of hepatitis failure. It remains unclear whether drug induced liver injury is more severe in patients with preexisting liver disease or if the injury is just less well tolerated. The two published instances of hepatic failure due to psoralen hepatotoxicity occurred in patients with known, preexisting cirrhosis.