Studies suggest several key aspects of STEM (science, technology, engineering, mathematics) integration for teachers, but translating the findings and recommendations of these studies into fruitful changes in teachers' classroom practices remains a challenge. In this study, an assessment of teachers participated in an intensive professional development STEM program was conducted to better understand their perspectives on the content of the program, their anticipated challenges to effectively implement STEM education in their schools, and the supports needed to help them overcome their challenges. Both quantitative (surveys) and qualitative (participant interviews) were used to collect data to examine the impact of program on teachers' content knowledge, their anticipated challenges, and the supports needed to integrate STEM in their classroom. Results showed that the majority of the participants reported that the program enhanced their knowledge and abilities on how to teach science through STEM approach. Participants also reported several anticipated challenges that will limit their integration of STEM in the classroom such as; lack of physical resources, dealing with students' expectations, attitudes, and abilities, lack of time for collaboration with other teachers, and other important administrative challenges. Participants also provided specific suggestions to support their integration of STEM education in their classrooms.