Nephrology as a full-blown specialty was born in the middle of th 20th century with the advent of kidney replacement therapy. As regards knowledge of kidney diseases, decisive steps forward were introduction of percutaneous kidney biopsy (with examination by immunofluorescence staining and electron microscopy), as well as investigation of individual nephron function by micropuncture and more recently molecular biology techniques. As regards therapy, nephrology benefited the tremendous development of phamacology with the advent of diuretics, hypotensive agents and immunosuppressive drugs. But the revolution of the time was actually the invention of hemodialysis and peritoneal dialysis as well as the first success of kidney transplantation, allowing a rapidly growing number of patients worldwide to survive renal insufficiency for decades. Access to renal replacement therapy gave rise to novel ethical issues, which has been the foundation of medical bioethics.