Jayne D. Treatment of ANCA-associated systemic small-vessel vasculitis. APMIS 2009; 117: 3–9. Much has been learnt over the last 30 years to optimize the use of immunosuppressive and glucocorticoid therapies that has allowed the publication of treatment guidelines. However, major unmet needs remain in the treatment of ANCA-associated vasculitis (AAV) and include refractory disease, only partial efficacy and toxicity of current drugs and the need for long-term regimens. Newer therapies, including mycophenolate mofetil, leflunomide and rituximab, are providing a real opportunity for improved outcomes of AAV in the future. The development of therapy has been facilitated by international clinical research networks but delayed by the complexities of studying an uncommon, multi-system disease.