The purpose of this chapter is to summarize the research relating to pediatric and neonatal intensive care environments in order to provide the reader with the best evidence to inform design decisions. The chapter begins with a summation of the meaning and role of evidence-based design (EBD). The subsequent section will describe the design research associated with each of several environmental components that apply to both PICUs and NICUs. The last two sections summarize research specific to each of these two settings.