With funding from the National Science Foundation, engineering schools at Northeastern University, Tufts University, Worcester Polytechnic Institute, and Boston University joined forces in an effort to increase the number of girls who develop an interest in science, technology, engineering, and mathematics (STEM) fields during the middle school years, as well as in STEM careers. The 4 schools for Women in Engineering (WIE) strategy was to form all-female teams to train teachers and to serve as in-class resources for them. STEM Teams developed gender equitable engineering units to be used in 8th grade science classrooms and helped middle school teachers implement the new units for the engineering strand of the Massachusetts Frameworks. The strategy was implemented in eight public school districts in the greater Boston area. The evaluation focused on how teachers and STEM team members experienced the program and what the impact of the intervention was on students. Teachers' and STEM Team members' perceptions were assessed through open-ended anonymous questionnaires completed after the implementation of the intervention. The impact of the intervention on students was assessed through comparing attitudes toward engineering, mathematics, science, and STEM fields and careers before and after the intervention.