To determine the question of the extent of fibrous intimal swelling in chronic transplant vasculopathy, of fibrous interstitial broadening and of tubular atrophy, we performed semi-quantitative histological examinations on 139 biopsy specimens, 70 removed kidney allografts and 35 allografts after autopsy, respectively. A positive correlation was found between vascular and interstitial changes. Morphometric analyses were done in 9 removed transplants and 2 normal kidneys, at which in each case 4 cortical regions including the supplying middle-sized and small arteries are examined. It was shown, that the extent of intimal swelling was variable and in the same sense also the degree of interstitial proliferation. Thus, the correlation as mentioned above is confirmed. Therefore, it is presumed that the extent of chronic transplant vasculopathy with reduction of the blood supply is most important to the formation of interstitial broadening and tubular atrophy. On principle other causes are possible and must be excluded by histological and/or angiographic investigations.