It is evident that the field of pediatric critical care is evolving rapidly, but the prime issue remains the proper delivery of scarce and expensive resources to the most patients. In order to do so it is necessary to determine where current resources exist. This has been difficult to accomplish accurately on a national basis, although it may be possible on a regional level. To achieve the final goal of building organized systems of care, the special needs of the critically ill and injured child must be recognized. Models of regionalization will provide the basic structure for the development of these systems. The Model for a Pediatric Critical Care System proposed by the California Critical Care Coalition and District IX of the American Academy of Pediatrics should be readily applicable to any region. It is hoped that the information and examples provided in this article will provide some guidelines for those interested in promoting regionalization of pediatric critical care across the nation.