A 34-year-old man with Sweet's syndrome associated with subacute necrotizing lymphadenitis is reported. Histological examination of an erythematous, painful, cutaneous plaque revealed a dermal interstitial neutrophilic infiltrate. A biopsy specimen obtained from an inguinal lymph node showed granulomatous formation, consisting of histiocytes, with central necrosis in the paracortex and macrophages in the sinus. Although the causes of the two diseases remain obscure, this appears to be the first report of Sweet's syndrome associated with subacute necrotizing lymphadenitis.