Differential attainment is a well-known phenomenon in medical education. Despite a strong impetus for institutions and researchers to move away from a 'student deficit model' when exploring the attainment gap, little attention has been given to understanding the experiences of Black, Asian and Minority Ethnic (BAME) medical students. Informed by the social construction of learning theory, this is the first national study to explore how multiple dimensions of the medical school environment impact academic performance of BAME undergraduate medical students across the UK. Using a sequential explanatory mixed-methods approach, the authors conducted a survey and facilitated three focus groups across medical schools in the UK between 2020-2021. Participants self-identified as being from BAME backgrounds. Quantitative analyses included descriptive statistics and bivariate analyses. Qualitative data were analysed using thematic analysis, subsequently identifying inductive themes. Three hundred sixty-two respondents completed the Phase 1 survey, and 17 participants participated in the Phase 2 focus groups. Although both survey and focus group participants identified facilitators to learning such as supportive relationships, students reported facing numerous barriers that they felt impeded their learning and performance. These barriers included limited access to educational resources, and undiversified curricula and medical school populations. Students also described both experiencing and witnessing various forms of racism throughout their educational journeys. Students encountered various difficulties throughout their medical training that they felt impacted their learning and performance. This study offers novel insights into the experiences of BAME students and builds upon previous research. It also reveals the pervasive nature of racism within medical schools, highlighting the urgent need for institutional changes. Educators and institutions must go beyond merely recognising these barriers and facilitators; they must proactively innovate and adapt. In doing so, they pave the way for inclusive learning environments that truly foster a sense of belonging for BAME students.