Systemic vasculitis is a group of inflammatory diseases of vessels of various sizes, with variable pathogenic mechanisms. Their causes are often unknown. This disease group is historically dominated by polyarteritis nodosa but also includes granulomatosis with polyangiitis, eosinophilic granulomatosis with polyangiitis, and giant cell arteritis. Immunologically, anti-neutrophil cytoplasmic antibodies (ANCA) are present in a group of small-sized vessel necrotizing vasculitis. The extremely severe prognosis of vasculitis has been modified by corticosteroids and immunosuppressive treatments. More recently, biotherapies, including rituximab in ANCA-associated vasculitis, mepolizumab in eosinophilic granulomatosis with polyangiitis, and tocilizumab in giant cell arteritis, have achieved remissions in more than 90% of patients and prevented relapses. They have also made possible to considerably reduce corticosteroid treatment and, consequently, its side effects. Vasculitis is now curable with a favorable prognosis.