Peer-learning is an effective way to assist students to acquire study skills and content knowledge, especially in university courses that students find difficult, and it is an effective adjunct to improve student retention. In 2014, Murdoch University in Perth, Western Australia, commenced Peer Assisted Study Sessions (PASS) in two first-year undergraduate subjects: a mathematics (statistics) unit and a business unit. The key finding in this evaluation was that while female mathematics students improved their final marks in response to attending a greater number of sessions per semester, male students achieved lower final marks on average. Although several studies have shown that in PASS-like programs gender tends to not be a significant factor relating to achievement, our results suggest otherwise. In this article we posit the observed differences in achievement attributed to gender arise from complex gender-related issues, including gender stereotypes, student gender ratios in class, the gender of the teacher relative to the gender of the student, and gender-related motivation, engagement, and subject choice. An approach to remediate gender-associated differences in achievement for PASS attendees is proposed.