We live in a world where awareness of ethnic and cultural diversity is an ever increasing reality. Business and education turn to the social sciences to inform them about how to manage and optimize cross-cultural interactions. Although much research has been done on the impact of cross-cultural interactions on a wide range of variables, one less researched area is the endocrine response to cross-cultural interactions. In this study we set out to investigate the endocrine response to cross cultural interactions and the impact of these interactions on perceived differences. To do so we measured the pre and post levels of the stress hormone cortisol of individuals communicating in dyads for 15 minutes. Results showed a significant impact of ethnic interaction on perceived differences and cortisol levels. Practical implications of these findings could have application in the areas of education, psychology, business and human relations in general. Implications for further research are discussed.