Latina SciGirls (2015-2018) is led by Twin Cities Public Television through a National Science Foundation grant to expand and study the SciGirls Emmy Award-winning transmedia project for engaging elementary and middle school-age girls in science, technology, engineering and mathematics (STEM). At its heart is a television series on PBS designed specifically for girls. Latina SciGirls is developing a Spanish-language series of half-hour television episodes showing groups of girls and their Latina STEM mentors investigating culturally relevant science and engineering problems of interest to Hispanic communities across the U.S. Television mentors and girls will be filmed in Hispanic communities in the southwest and southeastern U.S. and represent various cultural backgrounds and ethnicities including Mexican, Central and South American, Puerto Rican and Caribbean. The project is also creating a series of family and girl-friendly online video profiles of Latina STEM professionals showing the daily life of a female scientist or engineer, and will provide opportunities to connect girls and their families with in-person Latina role models via community outreach in diverse Hispanic communities across the country. XSci is leading the research effort to investigate: (1) Hispanic girls’ experiences in Latina SciGirls in terms of their ability to forge deeper and more personally relevant STEM connections and commitments (positive science identities) and; (2) Program-associated social dynamics occurring within their peer groups and families that may or may not support their engagement in STEM.