Psychological science is worldwide, but it originated earlier in some countries and regions than in others, and the course of development has differed among countries and regions. Psychology has also interacted with quite different cultural backgrounds in different regions of the world. The special issue of the International Journal of Psychology contains seven papers that treat the origins and development of psychology in most of the regions of the world. It includes countries and regions where psychology has a long history and has attained major status and also developing countries where psychology is more recent and is less well established. It includes papers on countries of European culture and also countries where psychology interacts with the background of Asian and Latin American cultures. The authors of the papers, all well known internationally, are all present or past members of the Executive Committee of the International Union of Psychological Science and so are well acquainted with world psychology and psychology in countries besides their own. All of the authors have done research in other countries than their own and so can place the development of psychology in their own regions within the context of world psychology. These contributions show both the common features of psychological science around the world and also the special problems and special opportunities of psychology in different regional and cultural settings.