The paper explores the potential of the diaspora in promoting the country of origin as a tourist destination, focusing on the case of the Portuguese diaspora in Hungary. Semi-structured interviews were conducted with members of the Portuguese diaspora and/or representatives of governmental entities of Portugal in Hungary. The findings indicate that diaspora members can be highly effective promoters and influencers of their country and region of origin at the international level. They can be powerful allies in promoting tourism and fostering sustainable development in their homelands. Results also suggest that the Portuguese diaspora in Hungary can influence potential tourists both online and offline, particularly through personal and professional networks, by sharing experiences, recommendations, and opinions. Additionally, they might engage in other promotional activities such as offering souvenirs and products. The paper concludes by identifying limitations, such as the small size of the Portuguese diaspora in Hungary, but also suggesting future research directions.