Relevant quote: Science is not a boy’s game, it’s not a girl’s game. It’s everyone’s game. Nichelle Nichols State, preferably single, research/case problem: Females remain under-represented across the fields of science, technology, engineering and mathematics (STEM). Numerous barriers have been identified impeding females to pursue STEM degrees. By understanding which factors explain behaviour focus can be directed to the constructs which have the highest prospects of resulting in behavioural change (David & Rundle-Thiele, 2018). Social marketing is capable of addressing complex social issues (Kubacki et al., 2015); however, there is a limited application in STEM fields (Roemer et al., 2020). Chapter overview Behavioural change is complex at the best of times. Understanding the barriers and enablers for change is essential for social marketers to focus their efforts on identified drivers known to facilitate or impede behaviour change. The importance of theory is noted in social marketing; however, recent reviews demonstrate that theory application is vague and/or not reported in sufficient details (Truong & Dang, 2017; Willmott et al., 2019). Behaviour change communication is essential to promote uptake of behaviours (Briscoe & Aboud, 2012); however, more work is needed to understand whether sustained behaviour changed is enabled as a result of the framing of messages received (Snyder et al., 2004). Informed by theory, this case study reports on a successful social marketing campaign seeking to increase female retention in STEM in a higher education sector, second to advance the use of theory in social marketing and third, to determine the effectiveness of message framing. This study extends social marketing’s capability to tackle underrepresentation of females in STEM.