Outmigration from rural territories is a worldwide phenomenon that is visible in many mountain regions and creates a perception of a landscape of abandonment. Nonetheless, a counterprocess has also occurred over the past decades of increasing immigration into marginal areas, including mountain areas in Europe. This article compares case studies from mountain municipalities in Austria, Italy, and Romania that have experienced an increase in immigration. Despite their common spatial features, these towns have shown different approaches to managing immigration. This study compared the responses of local communities to immigrants from various backgrounds. Each case study concentrated on the most relevant group of new arrivals in that municipality and provided an analysis of the background conditions and main influences on the integration process. The focus was at the municipality level, supplemented with a broader regional view where possible. The case study in Trentino, Italy, focused on internal migrants who were mostly young people, the study in Romania on amenity migrants, and the study in Austria on asylum seekers. Bearing in mind the diverse starting points and immense cultural diversity in the study areas, the manifold experiences of the integration performed by community action on both sides (new arrivals and local residents) point to 3 main aspects as crucial to integration: the presence of a supportive social environment, the engagement of local actors who broker contacts between the groups, and the availability of appropriate meeting spaces.