To demonstrate the 3D microvascular anatomy of the brain of the model organism Xenopus laevis Daudin scanning electron microscopy of vascular corrosion casts was correlated with light microscopy of stained 7 m thick serial tissues sections. Results showed that supplying arteries descended from the leptomeningeal surface without remarkable branchings straight to the subventricular zone where they branched and capillarized. Capillaries showed few H and/or Yshaped anastomoses during their centrifugal course toward the leptomeningeal surface where they drained into cerebral venules and veins. Apart from the accessory olfactory bulb and the vestibulecochlear nucleus where capillaries were densely packed, capillaries formed a widemeshed 3D network throughout the brain parenchyma and thus contrasted to urodelian brains where hairpinshaped capillaries descend from the leptomeningeal vessels into varying depths of the brain parenchyma. In about twothird of specimens, a closed arterial circle of Willis was found at the base of the brain. If this circle in Xenopus might serve the same two functions as in men is briefly discussed. Choroid plexuses of third and fourth ventricle were found to have a high venous, but a low arterial inflow via one small choroidal artery only. Findings are compared with previous studies on the vascularization of the anuran brain and discrepancies in respect to presence or absence of particular arteries and/or veins in Ranids, Bufonids, and Pipids studied so far are discussed with particular emphasis on the techniques used in the various studies published so far.