The purpose of this study is to examine international school secondary students' understandings of intercultural sensitivity and the life experiences they attribute as influencing their own development of intercultural sensitivity, including participation in four models of service programs offered at their school. With practitioners in the field of service-learning claiming that service-learning influences students' personal development, this study uses semistructured interviews and qualitative analysis to gain insights from students' perspectives about the influence of participation in service-learning programs and other life factors on their intercultural sensitivity. This study found that international school students have many formal and informal opportunities to experience difference; that although service-learning can influence the development of intercultural sensitivity, it does not necessarily do so; and that students are able to develop intercultural sensitivity through a variety of life experiences. (Contains 2 tables.)