Vasculitides occurring during the course of human immunodeficiency virus (HIV) infection are heterogeneous in their clinical presentation, time of occurrence, histological findings and etiological factors. Some of them can be directly attributed to HIV infection and their treatment might require new therapeutic approaches, such as plasma exchanges, specific antiviral agents and/or vasodilators. We report 8 cases of vasculitis associated with HIV. Five of them met the classification criteria of polyarteritis nodosa and had symptoms compatible with microscopic polyangiitis. Etiological agents were not identified. Although hepatitis B virus, hepatitis C virus (HCV) and other viruses or opportunistic agents were detected in some patients, HCV was suspected of being the etiological factor in only 1 of them. Focusing on viral and immunological features, the possible mechanisms of vasculitis development in HIV+ patients are discussed. Long-term follow-up indicates a clear benefit of regimens including antiviral agents, vasodilators and plasma exchanges. No deterioration of AIDS status was observed with this treatment and no relapse was recorded.