OBJECTIVE This study was undertaken to describe Doppler sonographic measurement of cerebral blood flow in anemia secondary to chronic renal failure and to compare the results with data gathered from healthy control subjects. We also aimed to compare vertebral and internal carotid artery blood flows to see whether any alteration of dominance in cerebral blood supply would occur. METHODS We studied 27 predialytic patients with chronic anemia resulting from chronic renal failure and 20 healthy control subjects by means of extracranial Doppler sonography. In these patients, blood flows of bilateral internal carotid and vertebral arteries were measured, and net vertebral artery, net internal carotid artery, and total cerebral blood flows were estimated. Statistical significance was observed between groups, and the data were correlated with hemoglobin level. Variation of the difference of the Doppler measurements between case and control groups by side (left or right) or disease status (patient or control subject) was analyzed. RESULTS From the assessed Doppler parameters, only cerebral blood flow and right and net vertebral artery blood flows had a significant difference between groups (P < .05) and showed a negative correlation with hemoglobin level. Vertebral artery blood flow was found to have significant interactions with disease status (P = .009) and side (P = .054). CONCLUSIONS Right vertebral artery blood flow is most prone to increase in chronic anemia of chronic renal failure. This effect also appears as increasing net vertebral artery blood flow and cerebral blood flow.