Cryoglobulins are immunoglobulins that precipitate in vitro when serum is incubated at temperatures lower than 37°C. Cryoglobulins are classified under three subgroups according to their components. Cryoglobulinemic vasculitis corresponds to manifestations associated with vascular occlusion by cryoglobulins or inflammatory manifestations induced by the deposition of cryoglobulins containing immune complex. Main manifestations are skin lesions, including vascular purpura, necrosis, kidney involvement, and peripheral nerve involvement. Initial work-up aims at identifying the underlying disease, which may be a B-lineage hematological malignancy, a connective tissue disorder, or a chronic viral infection like hepatitis C. Treatment and prognosis are closely dependent of the underlying disease.