There are several references in the literature highlighting the importance of the international scientific mobility studies and several examples of how this academic population has been characterized. Typically, the analysis of academic mobility has been conducted by applying extensive surveys to a “representative” sample, in a specific moment in time, in which the profile of the researchers, that are working or studying in a foreign country, is then inferred. These analyses may suffer of structural lack of representativeness since the target population is unknown. As a structural and inherent issue in this research field, this article presents the results provided by the Portuguese academic social network GPS (Global Portuguese Scientists). It uses a valuable and exclusive data set of the research experiences, provided by Portuguese researchers, to describe and understand the academic dynamic of these researchers over the last years. The analysis considers different socio-demographic characteristics and the type of research (position, scientific research area, duration of the experience) they have been doing. The analysis shows that GPS users are pulled to the core countries of the science world system and points out that each destination of the Portuguese diaspora is associated with specific features of the mobile researchers and their research activity.