Adult-onset Still's disease is a systemic disorder without specific histological feature. Diagnosis requires to rule out any other disorder including neoplasia. Nevertheless, patients with paraneoplastic adult-onset Still's disease have been reported. We report a patient with an adult-onset Still's disease who presented with a liver involvement at onset. Two years later, a liver angiosarcoma was diagnosed. This report underlines the difficulty of the diagnosis of the adult-onset Still's disease even in the presence of Yamaguchi et al.'s [J Rheumatol 19 (1992) 424-30] and Fautrel et al.'s [Medicine 81 (2002) 194-200] classification criteria and may suggest a link between the initial clinical picture and the discovery nearly two years later, of a liver angiosarcoma.