PROJECT SUMMARY / ABSTRACT Science, technology, engineering, and math (STEM) degrees provide access to rewarding, highly remunerated careers, and the opportunity to contribute solutions to society’s problems. Unfortunately, Latinas and African American women comprise less than 4% of the current STEM workforce. Gender stereotypes and a lack of relatable role models, mentors, and early exposure to STEM have been suggested to deter middle school girls away from STEM interests. This project will examine the effect of Seeds of Success, an out-of-school intervention designed to inspire girls to consider careers in STEM by countering gender and race stereotypes through relatable role models; promoting STEM self-efficacy through STEM workshops and activities; and encouraging alignment between cultural and STEM identities through community-based STEM projects. A total of 160 girls in grades 7-9 will be recruited every year to participate in mirror programs in Puerto Rico and New Haven, CT, two populations with high percentages of underrepresented and underserved students. Girls will receive mentoring from female STEM professionals from similar racial and ethnic backgrounds and will interact via webinars with additional diverse STEM role models to learn more about STEM careers. In addition, girls will be exposed to engineering, life sciences, and computer science concepts through online and in-person activities and workshops that promote critical thinking. Finally, girls will be empowered to undertake STEM Ambassadors projects that allow them to have an impact on their community through science. We hypothesize that the program will promote gains in STEM interest, self-efficacy and identity—potentially benefiting future career decisions. Effect will be measured with surveys administered before and after the program to participants and a control group. Longer- term follow-up surveys will track sustained impacts on high school graduation, college entrance, and choice of major. In addition to the 800 girls that the program will impact directly, at least 20,000 additional students and members of the community will be impacted through the STEM Ambassadors projects and the female STEM role model webinars that will be shared live and on Youtube. Thus, by implementing these culturally-relevant, asset-based STEM engagement strategies, Seeds of Success will improve the STEM outcomes of girls in high- need communities and retain the diverse talent we need in the 21st century.