Paraneoplastic strokes show a clinical picture different from those observed in stroke patients without cancer. Diffuse and progressive encephalopathy, either isolated or accompanied by focal neurological manifestations, is usual in disseminated intravascular coagulation, nonbacterial thrombotic endocarditis, and paraneoplastic vasculitis. The clinical presentation of paraneoplastic cerebral venous thrombosis includes severe, diffuse, and progressive headache due to intracranial hypertension, partial or generalized seizures, transient ischemia or cerebral infarct of venous origin, and progressive ischemic encephalopathy. The diagnostic process for paraneoplastic strokes is different from standard procedures for other types of stroke. Cerebral computed tomography (CT) and magnetic resonance imaging (MRI) can be normal in ischemic events caused by disseminated intravascular coagulation, or may show multiple images in several vascular territories in nonbacterial thrombotic endocarditis and vasculitis. Heparin may be effective in preventing cerebral infarction among patients with nonbacterial thrombotic endocarditis and does not increase the risk of hemorrhagic complications.