This mixed-methods case study examined the intercultural development of US students participating in a summer internship abroad program. Using Kelley's (1995) Construct of Cross-Cultural Adaptability and Bennett's (1986, 1993) Developmental Model of Intercultural Sensitivity, the study explored changes in cross-cultural skills and how students perceived cultural differences during the intercultural experience. Kolb's (1984) Experiential Learning Theory also provided a framework in understanding intercultural development. Data from pre and post-program surveys (Cross-Cultural Adaptability Skills Inventory), pre and post-program interviews and field observations provided insights into students' intercultural development. Although quantitative and qualitative data indicated growth in different dimensions, students reported improvements in coping with challenges, remaining open to new experiences, accepting cultural differences, and developing greater levels of independence and self-confidence. Some participants displayed greater understanding and sensitivity towards cultural differences, while other students did not. These findings underscore the importance of program interventions, such as guided reflections and cultural mentoring, to enhance intercultural learning. Results of this study suggest a short-term summer internship abroad program can have positive effects on participants' cross-cultural adaptability skills, including emotional resilience, flexibility and openness, perceptual acuity, and personal autonomy. Other beneficial outcomes include the positive influence on students' career and academic aspirations. Lastly, data analysis revealed the significance of participants' starting conditions and program design on student learning. Based on these results, international educators and practitioners can further address the challenges related to evaluating the effects of programmatic structures and facilitating effective short-term exchanges abroad. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]