Originally designed to enable young children with autism lacking functional communication to initiate requests and to describe what they observed, the Picture Exchange Communication System (PECS) has been the subject of an ever-expanding body of research and development. Thirty-four peer-reviewed published reports on PECS are analyzed in this article with documentation of research questions, methodology, and results. Findings suggest that PECS is providing people around the globe who have no or impaired speech with a functional means of communication. Refinements in methodology and additional questions that might be addressed in future research are discussed.