Because of progressive population ageing and epidemic diffusion of type 2 diabetes mellitus in industrialized Countries, we are attending a growing incidence of end stage renal disease. This phenomenon has induced researchers to study potential alternative methods of renal function replacement. Actually, only dialytic methodics and renal transplant make possible survival of patients with terminal uremia, but both these therapeutic approaches show important limitations. The ideal solution would be represented by the possibility to "regenerate" the injured organ. This is the purpose of Regenerative Nephrology, a new medical domain which tries to develop new therapies through stimulation and induction in humans of regenerative processes already observed in other species, like reptiles and fishes. Such an ambitious and fascinating purpose requires a deep knowledge of the intricate networks which regulate the production of the hormones and mediators involved in the tissue regenerative processes. In this field the kidney embryonic development phases can represent a fundamental study model to acquire information about the reparative mechanisms of the structure and function of this excretory organ.