Hemodiafiltration (HDF) is an extracorporeal renal-replacement technique using a highly permeable membrane, which offers combination of diffusion and convection to enhance solute removal in a wide spectrum of molecular weights. In this way, ultrafiltration exceeds the planned fluid loss in the patient, and replacement fluid must be administered to achieve the target fluid balance. Over the years, various HDF variants have emerged, HDF on-line has been developed. This article provides a brief review of the history of HDF all over the world and in Moldova. The Founding Father of diafiltration is L. Henderson who in 1967 published the first article on the use of ultrafiltration and fluid replacement (diafiltration) as a method of blood cleansing. Clinical and laboratory research attempted at identifying ‘‘uremic toxins’’ of various molecular size and stimulated the development of dialysis strategies aimed at their optimal removal by more biocompatible membranes designed for both diffusive and convective procedures.