The growing knowledge gap between the North and the South shows the need for innovative perspectives in the study of the mobility of scientists and skilled professionals. Today, more than ever, it is obvious that there is a need to recognize the importance of science and the production of knowledge for development, the value of international cooperation and the intervention of scientific diasporas as relevant actors. As globalization and technological advances have promoted new ways of contributing from a distance, the challenge now is to find the best way to involve emigrated human capital in the scientific and socioeconomic progress of developing countries. This article offers an evidence-based analysis of the transnational practices of scientists and skilled professionals from Colombia, India and South Africa living in Switzerland, and it examines the conditions and the opportunity structures that are necessary if they are to act as agents of change in the benefit of their countries of origin.