This study contributes to the understanding of the low level of non-marital cohabitation in Poland at the beginning of the XXI century. We employ an interpretative analysis of semi-structured interviews in order to capture the meanings and attitudes associated to non-marital cohabitation by a selected sample of young Poles. The results indicate that although cohabitation has begun to be interpreted as a testing period leading to marriage, attitudes towards it are still very ambiguous. The idealization of marital commitment hinders the spread of informal unions. Understanding the determinants of low cohabitation in Poland enables us to advance grounded hypotheses on its evolution in the near future and, more generally, to illustrate the ways in which local cultures influence the diffusion of behaviors.