Through the modification of a technique developed by Beeuwkes, microangiography, using barium sulfate, was performed on rabbit kidneys following perfusion fixation with gluteraldehyde. Gluteraldehyde is a rapid fixative which preserves tissues while creating few artifacts on the electron microscopic level. The vessels and tubules are preserved in an open-lumen state with sufficient hardness to resist the artifacts caused by high pressure renal artery injections. By injecting barium sulfate at high pressure through the renal artery it is postulated that microruptures are created in the glomerular tuft. This leads to opacification of the tubules and the demonstration of various anatomic configurations. Low pressure injections were used to selectively demonstrate the vascular anatomy. This method allows the demonstration of the vascular and tubular anatomy without specialized techniques. The mechanism of failure of opacification of the renal vein on conventional microangiography are discussed.