The Adult Onset Still's Disease (AOSD) is an entity of unknown origin characterised by fever, polyarthralgias or polyarthritis, a pharyngitis, a cutaneous eruption and elevation of leucocytes. We present observations of 17 patients diagnosed during the last thirteen years. Files of hospitalized patients with suspected AOSD have been examined in a retrospective study and Yamaguchi and Kahn's criterias applied in order to confirm the diagnosis. Treatments undertaken and the evolution have been noted. The sex ratio is 1.83; the middle age of intervening from 42 to 45 years. The middle delay for the diagnosis is 3 to 8 weeks. Fever, eruption and polyarthralgias are the most frequent clinical signs. Elevation of leucocytes, hepatic cytolysis and hyperferritinemia are usual. Constantly, inflammatory tests are increased and the rheumatoid factor and the antinuclear antibodies are negative. Yamaguchi's criterias have been met by all patients. The non steroïd anti-inflammatory drugs and corticoïds constituted the main treatment. In the evolutionary shield, 6 cases of remission have been noted. The other patients evolved toward the chronicity with either a systemic or an articular shape. In the two situations, a state of corticodependance got settled with necessity of association to immunosuppressive drugs. The diagnosis of AOSD is easily done on basis of Yamaguchi's criterias. Corticoïds can permit to control the bouts. There are 3 types of evolution: remission, chronic systemic or chronic articular shape.