In the study of mental health and migration, an increasing number of researchers have shifted the focus away from the concept of acculturation towards the stress present in the migratory experience. The bulk of research on acculturative stress has been carried out in the United States, and thus the definition and measurement of the construct has been predicated on that cultural and demographic context, which is of dubious applicability in Europe in general, and Spain in particular. Further, some scales have focused on international students, which down-played the importance of the migratory process, because it deals with a special subset of people who are not formally immigrating. The Barcelona Immigration Stress Scale was developed to measure acculturative stress appropriate to immigrants in Spain, using expert and focus group review and has 42 items. The scale shows acceptable internal validity, and, consistent with other scales, suggests that immigration stress is a complex construct.