The authors examined consecutive renal biopsies from 43 patients with minor glomerular abnormalities and from 35 patients with chronic tubulointerstitial nephritis (in the least affected glomeruli). The findings were evaluated according to WHO criteria of minor abnormalities. They found that significantly more frequently lipid drops were found in minor abnormalities (6:0), as well as changes in the capillaries of glomeruli (breakdown 1:7), wrinkling (15:29-highly significant even after correction of p)) in tubulointerstitial nephritis. The incidence in another 15 compared indicators there was not significantly different. With regard to the assembled results the authors consider the morphological finding of minor glomerular abnormalities as non-specific changes, and adaptational glomerular changes in response to various noxious substances. Therefore it is necessary to evaluate purely morphological findings of minor abnormalities carefully and in a differentiated manner, in particular in conjunction with treatment.