Why is it that some people assigned to live and work internationally perform very well, are satisfied with their assignments, and are valued by their organizations, and some do not do so well? Are those who adapt well to the local culture the same ones who do their jobs well? Providing cultural assessment and training seems to be a nice thing to do, but is there a way to justify the expense? In this article, Tucker provides some answers to these questions based on large-scale field research and more than 40 years of practice in assessment and training for international assignments. It is written for organizations striving to be the best they can be in their global markets through effective talent management.