AbstractA modification of the silver methenamine/Masson trichrome (SMMT) method was used routinely to stain 1μm paraffin sections of over 2000 renal biopsies. This method provided a reliable means of differentiating the morphological changes in renal biopsy tissue. The glomerular and tubular basement membranes were outlined by a fine black layer of silver nitrate; and, in contrast, proteinaceous deposits, red blood cells, and fibrin stained a bright red; connective tissues stained different shades of green.A detailed evaluation of the use of the SMMT technique for the light microscopy of glomerular, vascular, and interstitial changes indicated this to be an excellent, inexpensive method for evaluating most aspects of renal pathology. The use of thin sections combined with high magnification enabled the detection of minute immune complex deposits on or within the basement membrane or in mesangial regions. Although this method cannot replace ultrastructural and immunocytochemical techniques, it offers considerably more information than is presently appreciated and in many cases it has provided adequate information for the pathological classification of the tissue. (The J Histotechno1 17:131, 1994)