This study used dominance analysis to examine the relative importance of ninth grade, Mexican-origin adolescents' perceptions of academic support from significant others (i.e., mothers, fathers, teachers, and friends) in relation to aspects of academic success. Self-report and school record data were collected from 216 Mexican-origin adolescents living in intact families. The results revealed that teachers' academic support was the most salient predictor of academic satisfaction and grade point average for both female and male students. Academic support from the opposite-sex parent explained the most variation in academic motivation. Academic support from friends was least important in explaining academic outcomes. Implications for schools and educators are presented. (Contains 4 tables and 1 figure.)