Approximately one million international students were enrolled at U.S. universities in the academic year 2015-2016, and the number has been steadily rising since. Although these students aim to increase intercultural communication skills, international knowledge, and critical thinking skills, some international students experience difficulty participating in class discussion. Several studies have revealed a range of obstacles to full participation in in-class discussions, including language, cultural differences, academic differences, and social isolation. Among these barriers, some studies have identified emotional factors that significantly affect learning. This study was an in-depth exploration of the adverse emotional factors that impede discussion participation. Using a qualitative approach, twenty-three international students at one university were interviewed, and their responses analyzed. Students reported that fear, embarrassment, social isolation, judgment and discrimination were barriers to participation. These findings are discussed in the context of a framework for reducing negative emotional states, employing self-efficacy theory. This framework was applied to the interview results and the author's observation of international students' behavior in dormitories and university offices. These findings suggest a possible intervention approach for educators to help international students express themselves in the classroom.