Current data on therapeutic immunomodulation used to treat systemic vasculitides are reviewed in this paper, which also discusses ongoing and future developments in the field. In vasculitides associated with anti-neutrophil cytoplasmic antibodies, rituximab is a validated induction treatment that can serve as an alternative to cyclophosphamide and must be followed by maintenance treatment. In addition, the usefulness of rituximab as maintenance treatment was established recently. Immunoglobulins can be helpful adjuncts, most notably in patients with severe immunodepression. Plasmapheresis is indicated in patients with severe renal failure and may have a role in the treatment of alveolar hemorrhage syndromes. Mepolizumab has produced encouraging preliminary results in eosinophilic granulomatosis with polyangiitis (Churg-Strauss). Rituximab can be used in cryoglobulinemic vasculitis associated with hepatitis C virus infection when antiviral therapy fails or the disease is severe. Very low doses of interleukin-2 may be helpful in refractory forms. Rituximab is also an option in essential mixed cryoglobulinemia with uncontrolled vasculitis despite glucocorticoid and/or immunosuppressive treatment. In polyarteritis nodosa associated with the hepatitis B virus, a combination of short-course glucocorticoids, plasmapheresis, and antiviral therapy produces excellent outcomes. Intravenous immunoglobulins are used to treat Kawasaki disease, in which they diminish the incidence of coronary artery aneurysms. Several prospective controlled trials are currently assessing tocilizumab in giant-cell arteritis. Rituximab has useful effects in systemic vasculitis associated with rheumatoid arthritis. In Goodpasture's syndrome, plasmapheresis is indicated to clear the antibodies to glomerular membrane antigen, which can induce glomerulonephritis.