The intent of this study was to assess the perceptions and actions of Wyoming principals concerning their role in supervising and evaluating teachers. A survey was sent to all 286 principals in the state of Wyoming, of which, 143 returned surveys, a response rate of 50%. Findings suggested that principals utilized supervisory behaviors more often than evaluative behaviors. Elementary principals perceived their evaluative practices as significantly more prevalent than secondary principals. Furthermore, principals indicated that their greatest frustrations in supervising teachers were time, the evaluation instrument, and teachers' unwillingness to change. Additionally, findings suggested that Wyoming principals utilized classroom walkthroughs because they provided a snapshot of teaching and provided a medium for providing feedback. In regards to developmental supervision, principals indicated that novice teachers received much more supervision than veteran teachers. However, their reported use of differentiated supervision only applied to teacher autonomy concerning professional development goals. Principals reported that teachers had little input concerning the methods by which they were supervised. Finally, a majority of the Wyoming principals felt that improvement plans were effective at changing mediocre teaching behaviors, but 40% were speculative that such plans truly remediated poor teachers.Keywords Supervision . Evaluation . Formative . Summative . Principal perceptions As both the political and public sectors call for excellence in schools, the demand for accountability trickles down to all school personnel including principals (Ovando Educ Asse Eval Acc (2011) 23:243-265