Adult-onset Still's disease (AOSD) is a rheumatoid disorder characterized by high fever, polyarthritis, leukocytosis, hyperferritinaemia, and mild liver involvement. We describe the case of a patient with AOSD with severe liver dysfunction. His serum levels of interleukin-10 and 18 showed a similar trend to his disease activity. Drug lymphocyte stimulation tests were positive for three drugs in the patient. Hypercytokinaemia was controlled by plasma exchange therapy.