ABSTRACT. Vascular endothelial growth factor (VEGF) is transcribed in the VEGF120, VEGF164, or VEGF188 isoforms, which differ in receptor binding, matrix association, and angiogenic activity. This vascular growth factor has been implicated in the development of the renal vasculature, but the role of the distinct VEGF isoforms remains unknown. In the present report, renal angiogenesis and arteriogenesis were studied in VEGF120/120 mice, expressing only the short VEGF120 isoform. In VEGF120/120 mice, ingrowth and survival of capillaries in glomeruli, remodeling of peritubular capillaries, vascular coverage by pericytes, and branching of renal arteries were all severely impaired, causing abnormal glomerular filtration and impairing renal function. The arterial branching defect might be related to a reduced expression of renin, a presumed renal arterial branching factor. Glomerulosclerosis and tubular dilation possibly resulted from renal ischemia caused by vascular defects. Thus, VEGF164 and VEGF188 not only mediate angiogenesis, but they also play an essential role in renal branching arteriogenesis.