There is a broad literature that depicts the relationship between mothers' and teachers' autonomy support on students' adjustment at school; yet the mechanisms underlying this link have received less attention. Grounded in self-determination theory (SDT), the present study aimed to address this gap in the literature by testing a model where basic psychological needs satisfaction and their frustration act as mediators in the association between autonomy support and school adjustment. The sample consisted of 271 Mauritian adolescent students (127 boys, 144 girls) in 10th and 11th grades (mean age of 15.5 years old) who responded to a questionnaire measuring their perceived relationships with their mother and teachers as well as their academic, social, and emotional adjustment. Path analyses showed that basic psychological needs satisfaction and frustration mediated the relationship between perceived autonomy support and school adjustment. However, distinct patterns of mediation were observed from mothers and teachers. In addition, gender differences were detected in perceived teachers' autonomy support, the need for competence, and adjustment dimensions. These results are presented and discussed based on SDT. The limitations and implications of the present study are also highlighted.