Understanding teachers’ attitudes and perceptions of STEM teaching is a key pathway to enhance effective STEM teaching. Inarguably, teachers are the cornerstone of educational quality and play a central role in students’ academic performance. Specifically, the pedagogical strategies teachers employ and their effective use in the classroom are strong determinants of students’ enrollment or retention in STEM fields of study and eventual careers. This study sought to explore the experiences of high school STEM teachers in Qatar, focusing on the pedagogical approaches they utilize and the challenges they encounter, with the aim of delving into how these approaches and barriers affect the teaching of STEM in the country’s high schools. The study’s design is observational, with data collected using a survey of 299 secondary high school STEM teachers (11th and 12th grades). To attain the goal of this study, we examined the barriers perceived to impede engagement in effective STEM teaching from high school teachers’ perspective. The study’s findings pointed to the influence of student- and school-related factors in shaping STEM teaching. Significant differences were detected based on teachers’ gender, grade level of teaching, age group, and university education. Logistic regressions revealed that teachers’ demographic attributes, including age group and university education, affect their likelihood to use STEM pedagogies in class. This likelihood was significantly affected by student-related barriers and the learning resources/materials employed in classrooms. These findings postulate critical evidence in directing the development of successful STEM learning practices within Qatar’s high schools.