Necrobiotic xanthogranuloma (NXG) is a rare, progressive, non- Langerhans cell histiocytosis characterized by multiple yellowish indurated plaques and subcutaneous nodules that frequently involve the face, trunk, and extremities. Extracutaneous manifestations and paraproteinemia are common. Here, we report the case of a 47-year-old female who referredto the Dermatology Clinic of Razi Hospital, Tehran, Iran with complaints of a yellowish swelling on her right buttock after an intramuscular injection of penicillin. A similar lesion gradually developed on her supraorbital areas after several months. Histopathological findings included granulomatous inflammation of subdermal tissue with necrobiotic foci, which confirmed the diagnosis of NXG.The patient was treated with an intralesional injection of triamcinolone and oral prednisolone. After 12 months of treatment, the plaques became considerably flatter and smaller.