BACKGROUND Lymphadenopathy is found in about 65% of patients with adult-onset Still's disease and is histologically characterized by an intense, paracortical immunoblastic hyperplasia. Adult-onset Still's disease has not been previously described as an etiology of suppurative necrotizing granulomatous lymphadenitis. METHODS We describe a 27-year-old Greek man who manifested prolonged fever, abdominal pain, increased inflammatory markers, episodic skin rash and mesenteric lymphadenopathy histologically characterized by necrotizing granulomatous adenitis with central suppuration. Disease flares were characterized by systemic inflammatory response syndrome with immediate clinico-laboratory response to corticosteroids but the patient required prolonged administration of methylprednisolone at a dose of above 12mg/day for disease control. After an extensive diagnostic work-up, which ruled out any infectious, malignant, rheumatic or autoinflammatory disease the patient was diagnosed as having adult-onset Still's disease. The patient is currently treated with 4mg of methylprednisolone, 100mg of anakinra daily and methotrexate 7.5mg for two consecutive days per week and exerts full disease remission for six months. CONCLUSIONS To the best of our knowledge this is the first report of suppurative necrotizing granulomatous lymphadenitis attributed to adult-onset Still's disease. This case indicates that the finding of a suppurative necrotizing granulomatous lymphadenitis should not deter the consideration of adult-onset Still's disease as a potential diagnosis in a compatible clinical context; however, the exclusion of other diagnoses is a prerequisite.