This study explored the situational interest and emotional valence of 13-year-old students (N = 94) participating in a five-session science course. The relationship between students' situational interest and emotional valence and their individual interest was also studied. During each session, students participated in a collaborative learning task. Before and after each task, students' situational interest and emotional valence were measured through a single-item self-report questionnaire. Individual interest was measured by the Task Interest Inventory scale at the beginning of the course. Students showed increasing levels of emotional valence after each collaborative learning task; however, they only reported significantly higher situational interest after the first task. Furthermore, the relationship between students' emotional valence and their individual interest frequently decreased after collaborative learning tasks. The findings suggest that collaborative learning could be a potential factor in changing situational interest. Areas for further research are provided.