The aim of this article is to analyse the factors affecting the motivations of immigrant entrepreneurs to generate an entrepreneurial gain (positive impact on home and host countries). We consider that positive reasons for emigrating can increase transnational entrepreneurship and mutual benefits for both societies. To test this hypothesis we present a model using Structural Equation Modelling (SEM). This model explains the relations between motivations, cultural similarities, institutions and transnational linkage potentials. We designed an ad hoc search of Argentinean entrepreneurs established in Spain, both as EU citizens and without legal EU status, using online social networks. We applied an online questionnaire to 214 such entrepreneurs. We conclude that institutional rules (formal and informal) greatly influence the location decisions of firms and immigrant entrepreneurs’ motivations for starting transnational business because they provide the frame for the development of profitable opportunities.