While the immigrant population in Finland is proportionally among the smallest in Europe, the workforce is, as in most other industrialised countries, ageing at an accelerating speed. As a consequence, the new Finnish immigration policy has been reoriented towards increasing pro-active support of a larger work-related migration with a special emphasis on need for better integration of immigrants. To promote immigration and successful post-migration integration among immigrants by means of scientific research, the two priorities addressed in these projects were put forward: (1) a proper investigation of the most pertinent factors are involved in the adaptation process of the immigrants and determine adaptation outcomes at different stages of migration and integration, and (2) the development of research based tools for both the authorities of the receiving society to help them to promote immigration and to facilitate the integration of immigrants, and for the potential and actual migrants to help them to be better prepared for and to overcome difficulties involved in the integration process. These studies were the first longitudinal large-scale researchs investigating the influence of the pre-migration stage on post-migration integration and adaptation among voluntary migrants. Alongside providing means to promote social integration and psychological adaptation of these immigrants, the study also promoted positive development of inter-group relations in the host societies and aimed to prevent racism and xenophobia.