Students report that teachers bully them, but a review of the literature indicates that little attention has been given to teacher-to-student bullying. This study used a mixed-methods approach to investigate elementary teachers' perceptions of seriousness and their intent to intervene in teacher bullying incidents. Results indicated that teachers categorize bullying based on consequences for students rather than the form of the bullying. Teachers identified the underlying factors of denial of access and belittling bullying actions as types of teacher-to-student bullying. The original types of physical, verbal and relational bullying were absorbed into these new categories. Denial of access includes actions that prohibited a student from participating in activities or rejection of a student's request. Belittling refers to actions or words that humiliate a student. Their sense of accountability, incorporating perceived seriousness and intent to intervene, was greater for peer bullying than teacher bullying and higher for forms of bullying that have physical rather than socio-emotional consequences. Participation in peer bullying prevention and intervention professional development was not associated with teacher responses, but teachers with more experience had higher levels of accountability for all forms of bullying. Teachers also indicated an awareness of teacher bullying in their schools. Some expressed zero tolerance while others felt that teacher bullying did not have serious consequences and was warranted to meet instructional goals. The findings suggest that further research is needed to expand the knowledge base in an effort to develop best practice and school policy.