In the present study, we examined empirical evidence for a concept of a “migrant personality” using the attachment framework. We compared Polish immigrants in the Netherlands to the Poles living in Poland measuring their secure and dismissing attachment styles, while controlling for age, gender, and education in both samples. The results showed that immigrants are more secure and more dismissing than their fellow countrymen (p < .001). Furthermore, we examined, whether attachment styles might be influenced by the host culture. For that purpose, we subdivided the sample of immigrants into 11 cohorts (each cohort differentiated from the other by two more years of residence) and we compared the mean scores on secure and dismissing attachment styles in consecutive cohorts of immigrants. We observed that the mean scores on secure and dismissing attachment remained similar over cohorts of immigrants. Moreover, the differences between immigrants and non-immigrants were of similar magnitude across cohorts. This suggests that the attachment styles of immigrants are not influenced by the host culture, and that the observed differences in attachment styles between immigrants and nonimmigrants last over time, and presumably, existed prior to emigration. Finally, we found that secure attachment was a stronger predictor of psychological health in the emigrant sample than in the in-country sample. In sum, evidence for a migrant personality has been found. This personality, as the results suggest, is functional for immigrants.