Insufficient international coordination of medical research can result in repetition of studies performed in other countries. Renal biopsy is a valuable diagnostic method; it was broadly used for research in the former Soviet Union. The number of biopsies has decreased since 1990; but medical research is on the increase today. Therefore, the purpose of this review was to remind that, performing renal biopsy or other invasive procedures, the risk-to-benefit ratio should be kept as low as possible. Renal biopsies were taken for research from patients with glomerulonephritis, pyelonephritis, amyloidosis, renovascular hypertension (in some studies from both kidneys), essential hypertension, alcoholism, diabetes mellitus, in congenital hydronephrosis and other urinary tract anomalies. About one third of the biopsy cylinder was routinely embedded in epoxy resin. The epoxy resin sections were made for research but not used for diagnostics, the latter being performed mainly on the basis of paraffin sections and immunofluorescence. Extensive use of renal biopsies without silver impregnation and electron microscopy was accompanied by over diagnosis of glomerulonephritis and corresponding overtreatment. Furthermore, the concept of hypoplastic renal dysplasia, developed on the basis of renal biopsy, probably interfered with the morphological diagnosis of Alport syndrome.