Glucose is the principal energy source for the mammalian brain. The presence of glucose transport proteins is essential to supply glucose to the neurons and glia within the brain. At least three glucose transporter isoforms have now been identified, and are thought to play a significant role, in the brain. This review describes our current understanding of cell-specific glucose transporter expression in brain, which includes GLUT1 (55-kDa form) present at a high concentration at the blood-brain barrier as well as in parenchymal cells (45-kDa form), most likely in astrocytes, GLUT3 expressed in neurons, and GLUT5 in microglia. We discuss some potential implications of this glucose transporter heterogeneity for cerebral metabolic activity.