Within the current context of globalisation, trasnationalism has acquired importance as a social phenomenon and an object of study, since it shows the value that the diasporas' own decentralized mechanisms have in promoting development in the countries of origin. In particular, scientific diasporas have the potential to benefit science and technology in their regions of origin in ways that go beyond the traditional institutional set-up. “Brain drain” and the growing world knowledge gap justify these innovative forms of knowledge transfer carried out by non-state actors, insofar as knowledge is viewed as a key catalyst for reducing poverty. The Colombian scientific diaspora is a classic case of reference having been the first to put the idea of a “scientific diaspora option” into practice, through the creation of the Caldas Network linking Colombian scientists abroad with the scientific community back home. The technical and human structure that made the Caldas Network possible, celebrating its rise and then lamenting its fall, had its origins in Switzerland. Despite the lack of sustained support due to discrepancies in Colombia's science and technology policy, this structure continues to work in a dynamic way. Nevertheless, very little is known about it. The purpose of this article is showing the innovative decentralised trasnational practices of the Colombian scientific diaspora in Switzerland, which has managed to boost development in Colombia. The article is based on the results of research into skilled migrants from developing countries living in Switzerland. This research, the first of its kind in Switzerland, included fieldwork done during 2006 and 2007, through in-depth interviews of a qualitative nature, and it also included two workshops. The results offer a diagnostics of the situation and examine transnational practices and the needs of scientific diasporas from the South who live in the North. The article provides empirical evidence of the transnational practices of the Colombian scientific diaspora in Switzerland, showing the value of its resources for promoting development and Colombia's science and technology agenda in particular. Precise transformations are revealed, for example, the strengthening of specific research areas because of their contribution to the creation of a critical mass on issues such as the environment, ICT’s and medicine or influencing the design of science and technology policies. Although affective capital and the ability to mobilise are traits of the Colombian scientific diaspora, the support of a consistent scientific policy is needed to capitalise on its resources. The conclusion is that attempts should be made to revert the tendency of the dynamic action of the Colombian scientific diaspora to advance faster than the local public policies which recognise and take advantage of it, through its inclusion in the development agenda. The hope is that this will see its decentralized trasnational activities, carried out in the interests of the development of Colombia, continue and expand over time.