The representation and success of women in Science, Technology, Engineering, Mathematics, and Medicine (STEMM) have sparked discussions, given their underrepresentation in these traditionally male-dominated fields. While women comprise 40% of STEMM undergraduates, senior-level positions see this figure drop below 20%. Research suggests that gender disparities in STEMM participation result from motivational differences, rather than competence. Exploring the reasons for these disparities are important as they can have significant consequences for the acknowledgement of women in STEMM, the maintenance of their STEMM discipline, and future careers. As such, this study explored how the experiences of 13 female undergraduates in Australian STEMM programs impacted their motivation and persistence in their degree. Through face-to-face semi-structured interviews, analysed via reflexive thematic analysis, five themes were constructed, encapsulating diverse experiences shaping female undergraduates in STEMM, influencing self-efficacy, determination, and well-being. Early exposure and environment were pivotal, acting as motivators or deterrents. Additionally, peer support was suggested as being crucial, fostering belongingness in the male-dominated space. Participants also grappled with recognition challenges, influenced by gender imbalances and a lack of role models. Intimidation was evident, leading to thoughts of dropping out, but passion drove persistence amid these challenges. The research increases awareness and understanding of the challenges faced by female undergraduates in STEMM, offering valuable insights for developing strategies to enhance their university experiences and promote success in future STEMM careers.