One thousand and ninety-four normal human kidneys and 18 abnormal (with duplication of the ureter) were studied by the corrosion method and pyelography followed by topometric and mathematics analyses. It was found that the renal pelvis is a calicopelvic complex built up of renal calices, urine ducts and renal pelvis. Before opening into the renal pelvis, renal calices join together forming urine ducts (superior and inferior; or superior, middle and inferior; or superior, middle anterior, middle posterior and inferior) which transport urine to the container, the renal pelvis. It can be seen that groups of renal calices with pyramids and their surrounding cortical substance form the renal excretory sectors of the kidneys where the processes of uropoiesis and transportation of urine through elements of the nephron and calicopelvic complex take place. These are two (superior and inferior), three (superior, middle and inferior) or four (superior, middle anterior, middle posterior and inferior) renal excretory sectors. The existence of renal excretory sectors is proved by congenital anomalies of the calicopelvic complex such as duplication of the ureter, where urine ducts of the superior and inferior renal excretory sectors do not form a renal pelvis but run separately to the urinary bladder. On the basis of anatomical data obtained, renal excretory sectors may be distinguished, analogous to bronchopulmonary segments in lungs. These data about renal excretory sectors will contribute to further improvement in the operative technique of renal partial resections as well as to anatomical nomenclature.