The granulomatous disorders discussed in this review are Wegener's granulomatosis (WG), lymphomatoid granulomatosis (polymorphic reticulosis) and "idiopathic midline granuloma". The treatment of choice of WG is combined therapy with corticosteroids and cyclophosphamide. Severely ill patients may be treated with intravenous bolus infusions of cyclophosphamide. Otherwise oral administration is used. Therapy must be adjusted according to leucocyte and thrombocyte counts. After clinical remission cyclophosphamide must be continued for at least a year under hydration sufficient to cause nycturia in order to protect the bladder mucosa. Corticosteroids can be withdrawn 9-10 months after clinical remission. Relapse of WG can be identified by clinical and laboratory (ESR, CRP, HB, urinary sediment) findings, including detection of anti-neutrophil cytoplasm antibodies (ANCA). Alternate treatment with azathioprine or trimethoprim/sulfamethoxazole may be used in patients with localized or smoldering disease. Furthermore trimethoprim/sulfamethoxazole may be used as adjunctive treatment. Lymphomatoid granulomatosis appears to be a T-cell lymphoma and should be treated aggressively with combination cytotoxic therapy and irradiation of localized manifestations. "Idiopathic midline granuloma" does not seem to exist but appears to be either WG or lymphomatoid granulomatosis when repeated biopsies are examined with monoclonal antibodies and/or serum examined for ANCA.