With the number of international migrants globally reaching an estimated 272 million (United Nations report, September 2019), the need for intercultural training is stronger than ever. Since its first edition, this handbook has evaluated the methodologies and suggested the best practice to develop effective programs aimed at facilitating cross-cultural dialogue and boosting the economic developments of the countries mostly affected by migration. This handbook builds and expands on the previous editions by presenting the rational and scientific foundations of intercultural training and focuses on unique approaches, theories, and areas of the world. In doing so, it gives students, managers, and other professionals undertaking international assignments a theoretical foundation and practical suggestions for improving intercultural training programs.