This study aimed to adapt the Perceived Self Efficacy toward STEM Knowledge Survey, developed by Lee, Hsu, and Chang (2019), into Turkish to measure teachers' self-efficacy perceptions regarding STEM education. For this purpose, validity and reliability analyzes of the survey were made. Participants were 204 in-service teachers who were working in different branches and from various cities in Turkey. A confirmatory factor analysis was performed to investigate whether the survey showed a similar structure with six factors and 30 items as the original version. The study findings showed that the adapted survey consisted of six factors, namely, scientific inquiry, technology use, engineering design, mathematical thinking, and synthesized knowledge of STEM and attitudes toward STEM education. Also, the t-test results of 30 items in the survey were found to be significant. The Cronbach's Alpha reliability coefficient was calculated as 0.972. The results demonstrated that the Turkish version of the Perceived Self Efficacy toward STEM Knowledge survey consisting of 6 factors and 30 items was a valid and reliable measurement tool.