The ANCA associated vasculitides (AAV) comprise are a group of conditions characterized by inflammation and necrosis of small and medium-sized blood vessels. They comprise Wegener's granulomatosis, Churg–Strauss syndrome and microscopic polyangiitis. Early diagnosis and treatment is important as the presence of advanced disease at diagnosis limits the potential benefit of therapy. The aim of this document is to provide guidelines for the management of adults with systemic vasculitis. The guidelines concentrate on the indications for using cyclophosphamide and the different therapeutic regimens available. The guideline does not cover the treatment of children or other types of systemic vasculitis. The target audience is rheumatologists, nephrologists and general physicians, together with trainees and nurse practitioners.