Evidence to guide assessment and management of patients with vasculitis is lacking for many important clinical questions. The evidence surrounding several common questions about management of vasculitis was reviewed. Patients with giant cell arteritis (GCA) are at risk for developing extra-cranial large vessel inflammation. Clinicians should be aware of this complication and search for large vessel involvement in patients with GCA who have ischemic symptoms. Research is needed to define optimal strategies to identify patients with such complications. Because of the hazards of chronic corticosteroid use, alternative therapies for patients with GCA have been sought but thus far no clear alternatives have been identified. Anti-neutrophil cytoplasmic antibodies (ANCA) are associated with small-vessel vasculitis, including Wegener's granulomatosis and microscopic polyangiitis, but changes in ANCA titers should not be used as a surrogate biomarker for disease activity. Several immunosuppressive agents can be used for maintenance therapy after induction of remission in patients with ANCA-associated vasculitis, with no firm evidence that one agent is superior to others. Collectively, this review shows that more research is needed to provide a firmer body of evidence to support clinical decision-making for patients with vasculitis.