After elimination of infectious causes, neoplastic causes and the systemic autoimmune disease of connective tissue, a patient with high fevers over 39 °C was diagnosed with Stills disease. High doses of prednisone led to resolution of symptoms, however after reducing the doses of prednisone to 15 mg, high fevers over 39 °C returned, as well as joint pains. The high doses of prednisone led to decompensation of diabetes mellitus even with 4 daily insulin dosages. Therefore it was proceeded to regular subcutaneous administration of anakinra once a day. Anakinra enabled the reduction of prednisone to as much as the currently administered 2.5 mg a day, but it has not so far allowed for removing glucocorticoids from the treatment completely. Activity of the disease is shown by the findings within the FDG-PET/CT examination. At the time of maximum activity of the disease there was distinct lymphadenopathy with pathological accumulation of FDG visible as well as increased accumulation of FDG in the hematopoietic bone marrow. As the disease activity decreased, the size of nodules regressed and FDG accumulation in both the lymphatic nodes and bone marrow declined. FDG-PET/CT is a suitable method for monitoring the activity of Stills disease.Key words: anakinra - Adult-onset Stills disease.