The current knowledge of human polycystic kidney disease (PKD)--its morphology as well as the current biochemical and molecular understanding of the disease- has been enormously aided by the existence of a variety of animal models. In mice, several spontaneous mutations have been identified that give rise to PKD. Furthermore, it has been possible to create experimental models of renal cystic disease by genetic manipulation. All these different models have been very informative in studying the role of growth hormones, cell differentiation and hyperplasia, ionic transport, oncogene expression and changes in extracellular matrix (ECM) composition during the development of PKD. Furthermore, they have allowed investigators to test different therapeutic approaches in vivo. This article will review the characteristics of the most common murine models of PKD, some of their current uses and the future role of these animal models in the understanding of human renal cystic disease.