Summary: There exists a gap between what is espoused in the professional and scholarly arena regarding possible benefits of students learning the history of mathematics and teachers’ perceptions of the use of the history of mathematics in curriculum. The purpose of this large scale research study was to gain understanding of the high school mathematics teachers’ perceptions related to the integration of the history of mathematics into their instruction. In particular, we sought to identify those factors that encourage or discourage high school teachers’ choice to include the history of mathematics as a systematic part of their mathematics courses. A total of 367 teachers, 12\% of all high school mathematics teachers from one of the USA states, participated in an on-line comprehensive survey, which was designed by the researchers. Several factors, such as teacher’s perception of the history of mathematics, teacher’s knowledge of the history of mathematics, time, high stakes testing, resources and other were identified and are discussed in this paper. We also offer recommendations for teacher professional development and suggestions for further research.