Purpose: This study seeks to identify 172 American elementary, middle, and high school teachers' perceptions of the major sources and intensity of the experience of mistreatment by a principal, the effects of such mistreatment, how these perceptions varied by demographic variables, teachers' coping skills, and teachers' perceptions of contributing factors. Design/methodology/approach: Participants completed a piloted, validated online questionnaire. Findings: The participants reported experiencing a wide range of abusive principal behaviors that resulted in serious or extensive harmful psychological/emotional, physical/physiological, and work-related effects to themselves, their work, and their families. An overwhelming majority (77 percent) indicated they would leave their job for another because of the harm caused by the principal's mistreatment. Mistreated teachers typically did not enact problem-focused coping strategies. Differences were found among teachers of various demographic categories for several variables. Originality/value: The findings of this current, quantitative study expand the authors' earlier qualitative research on the topic of teacher mistreatment; these are the only studies on this topic completed in the USA. Practical implications and suggestions for future research are included. (Contains 5 tables and 5 figures.)