This study explores changes in willingness to communicate in a second language (L2 WTC) inside multilingual classrooms among short-term exchange students. Data were collected from eight Chinese exchange students studying in three universities in Canada and two instructors teaching in one of these universities through in-depth interviews. Qualitative content analysis was conducted and three patterns of WTC changes were found: positive, negative, and no apparent changes. Three main factors underlying these changes were identified, which include students' perceptions of values in speaking up, sense of fitting in, and classroom environment. The two instructors from the host university provided positive comments and supportive suggestions regarding international students' L2 WTC and oral participation in multilingual classrooms. This study highlights the importance of sustaining short-term exchange students' L2 WTC through concerted efforts from students and teachers for maximizing the effectiveness of study abroad programs.