Background: Teachers may play a key role in reducing bullying by responding to incidents among students. Inspired by the theory of planned behaviour, several studies have investigated teachers' bullying-related cognitions as predictors of their responses to bullying. Aims: This study investigated whether six teachers' bullying-related cognitions (i.e., perceived seriousness, empathy, attitudes, self-efficacy and attribution of the bullying) predicted five student-perceived teachers' responses (i.e., Non-Intervention, Disciplinary Methods, Victim Support, Mediation and Group Discussion) over time. By examining this objective, more insight into student perceptions of teachers' responses to bullying could also be provided. Sample: In total, 999 upper elementary school students (M[subscript age] = 10.61 at Wave 1, SD[subscript age] = 0.90; 53.6% girls) and their 59 teachers (M[subscript age] = 39.61 at W1, SD[subscript age] = 11.60; 79.7% female) participated. Methods: A bullying questionnaire was administered in three waves to assess students' perceptions of the teachers' responses. Teachers reported bullying-related cognitions in the first wave. Multilevel analyses were used to investigate the relative contribution of the predictors on the teachers' responses over time. Results: None of the teachers' bullying-related cognitions significantly predicted the teachers' specific responses. Conclusions: The findings suggest that teachers' bullying-related cognitions are not reflected in their responses to bullying as perceived by students. Moreover, the findings indicate that students' perceptions of teachers' responses vary widely within classrooms and over time. Student- and teacher-reported teachers' responses might differ, and these possible differences should be taken into account.