Background. The use of plasma exchange (PE) for induction treatment of anti-neutrophil cytoplasm autoantibody (ANCA)-associated vasculitis (AAV), including Wegener's granulomatosis (WG), is still controversial. The use of PE in AAV is not commonly accepted in patients with a plasma creatinine <500 μmol/L (5.7 mg/dL) despite experimental support for involvement of ANCA in the pathogenesis of vasculitis.Methods. In a single-centre study from a tertiary referral centre, 32 patients with ANCA-positive WG were treated with standard immunosuppressive therapy, prednisolone and cyclophosphamide (CYC). In addition, they were randomized to treatment with or without initial PE. After 3 months, they were further randomized in a Latin square design to continue CYC or to change to cyclosporine A (CyA) for 9 months. The renal follow-up was at least 5 years.Results. Renal survival after 1, 3 and 12 months, and 5 years was significantly better in the PE groups. For all groups, the kidney/patient survival was 87.5%/93.7% at 1 year and 72%/56% at 5 years. All patients who were on dialysis when recruited were dialysis dependent 5 years later. There was no difference in morbidity or mortality between PE and control groups. Multivariate analysis demonstrated that PE improved renal survival (P < 0.01) at initial plasma creatinine levels >250 mol/L (2.85 mg/dL). Change from CYC to CyA did not influence rate of relapses or time to relapse.Conclusions. PE is recommended for induction therapy in WG patients at creatinine levels >250 mol/L (2.85 mg/dL), whereas previous randomized studies have limited PE to patients with creatinine >500 mol/L (5.65 mg/dL).