The objective of this study is to determine if minority and female students are more likely to persist in a science, technology, engineering, and math (STEM) major when they enroll in classes taught by instructors of their own race or gender. Using data from public 4-year universities in the state of Ohio, I analyze first semester STEM courses to see if the race or gender of the instructor effects persistence of initial STEM majors in a STEM field after the first semester and first year. Results indicate that black students are more likely to persist in a STEM major if they have a STEM course taught by a black instructor. Similar to previous findings, female students are less likely to persist when more of their STEM courses are taught by female instructors. (Contains 9 tables and 3 figures.)