Pervasive racial microaggressions (subtle and everyday racist acts) continue to challenge African international teaching assistants (AITAs) who strive to create conducive learning environments for students in a Canadian university. This qualitative study drew from racial microaggression theory and gathered data through semi-structured individual interviews to examine seven former AITAs' experiences of racism in their teaching assistant (TA) duties. Findings indicated that non-Black students doubted AITAs' subject-matter expertise, undermined their English communication skills, and often exhibited aggressive behaviours. Suggestions were made for current and future AITAs, course instructors, and universities that hire them to help improve the quality of AITAs' duties and their students' learning experiences. As previous studies largely overlook AITAs' experiences with racial microaggressions, this study makes significant contributions to the literature that, in turn, can inform policy.