We report the clinical, radiologic, and postmortem findings in two patients with paroxysmal nocturnal hemoglobinuria (PNH) who developed cerebral venous thromboses (CVTs). In contrast with those in most published cases, our patients did not have focal neurologic signs. Antemortem diagnosis of CVT had been made by MR cerebral venograms. We conclude that (1) PNH should be considered in any patient with stroke associated with iron deficiency anemia, hemolysis, hemoglobinuria, or hemosiderinuria; (2) PNH should be in the differential diagnosis of CVT; (3) the latter could present without focal neurologic signs; and (4) MR cerebral venography may be a reliable diagnostic alternative to cerebral angiography when CVT is suspected.