In earlier stages of parenchymal kidney diseases different changes are to be seen in angiography. No single sign appeared to be pathognomonic for glomerular nephritis, vascular disease or interstitial nephropathy. But the disproportionate frequency of some angiographic features assumed discriminatory value. Morphometry of the renal arteriograms discriminated statistically significant interstitial, vascular and glomerular diseases. The correct angiographical diagnosis was made in 76%.