The main objective of this two-year project is to develop, implement, and study an intervention that increases cybersecurity awareness and proficiency among high school teachers and exposes high school girls to cybersecurity activities and careers. This objective is spurred by the growing need for cybersecurity professionals coupled with the under-representation of women in this field. The Bureau of Labor Statistics reports that 18% of cybersecurity specialists are women. There has been increasing awareness that any scalable and sustainable effort to grow the workforce in cybersecurity cannot ignore pre-college students, indicating a need for more effective programs and support for high school aged children, especially girls. However, little is known about what it takes to engage adolescent girls in cybersecurity and combat the dramatic shortage of women in the field. This research study will generate evidence based knowledge about successful cybersecurity professional development for high school teachers and effective cybersecurity instruction for adolescent girls. The results will help other districts and schools justify the use of similar intervention models so that their teachers can break the barriers of stereotype threat and engage and retain girls in the cyber security field. More specifically, this innovative cybersecurity intervention includes the following: (1) A cybersecurity training program for high school teachers; (2) A curriculum made up of hands on, collaborative and ability building activities that help high school teachers introduce their female students to concepts and challenges of cybersecurity within single-sex school-based settings; (3) A female mentor network for high school girls and teachers, field trips that expose girls to opportunities in the field and involvement in a nation-wide high school forensics challenge that attracts thousands of students passionate about cybersecurity; (4) Ongoing technical assistance for teachers implementing the curriculum in order to ensure sustainability of the program in the partnering schools; Over the course of two years, at least 150 girls from 3-6 high schools in New York with racially, ethnically, and socioeconomically diverse student populations will be recruited to participate in the intervention. A quasi-experimental design, using a control group and pre-post tests in each school, will be utilized to examine the success of the intervention. Additionally, a qualitative research design will be utilized to document the process of learning that takes place and the experiences of the students. The impact on, and experience of, teachers in the program will also be studied using a pre-post test quantitative and qualitative research design. This mixed methods study will gauge impact and effectiveness in order to improve future efforts and to produce an evidence-based model for engaging girls in cybersecurity, which can be disseminated nationally.