Science communication is today a well-established —although young—area of research. However, there are only a few books and papers analyzing how science communication has developed historically. Aiming to, in some way, contribute to filling this gap, JCOM organized this special issue on the History of Public Communication of Science and Technology (PCST), joining 15 contributions, from different parts of the globe. The papers published in this issue are organized in three groups, though with diffuse boundaries: geography, media, and discipline. The first group contains works that deal descriptively and critically with the development of PCST actions and either general or specific public policies for this area in specific countries. A second set of papers examines aspects of building science communication on TV or in print media. The third group of papers presents and discusses important PCST cases in specific areas of science or technology at various historical moments.