We have presented a case report of a 56-year-old Mongoloid female with clinical and pathologic evidence of Alzheimer's disease concurrent with cerebral amyloid angiopathy (CAA) and intracerebral hemorrhage. Although this quartet of events might be expected to have coincided in a single patient, we believe this is the first reported case to present in such a fashion. Because of the high incidence of hemorrhage associated with CAA and the even higher incidence of CAA in Down's syndrome patients, the finding of stroke in this population should be considered secondary to this process until proven otherwise.