The antineutrophil cytoplasmic antibody (ANCA)-associated systemic vasculitides (AASVs) include granulomatosis with polyangiitis and microscopic polyangiitis. These conditions are characterized by small-vessel inflammation and necrosis, predominantly in pulmonary and renal vascular beds. Untreated AASV has a poor prognosis, although the advent of effective immunosuppressive therapy (the mainstay of which remains cyclophosphamide with high-dose corticosteroids) has markedly improved patients' survival (78% at 5 years). Patients with AASV, however, continue to have an increased mortality compared to the general population. Mortality is greatest in the first year after diagnosis and remains consistently elevated in subsequent years. Patients with AASV also experience increased rates of infections, malignancies and cardiovascular events as compared to the general population. Current treatments for AASV, although effective in controlling the aggressive systemic disease, incur substantial long-term toxic effects. Long-term immunosuppressive therapy also has notable deleterious effects on bone health and fertility. The long-term safety profiles of biological therapies (such as rituximab) are yet to be evaluated in patients with AASV, but represent a promising treatment option. The challenge for the future is to develop specific therapies with improved safety profiles that can cure these diseases.