The purpose of this study was to determine whether students’ perceptions of their relationships with teachers and academic achievement are associated, and explore whether ethnicity, gender or socio-economic status moderate those associations. Specifically, sixth graders’ perceptions of relationships with their 5th grade teachers were found to correlate with standardized achievement test scores. Furthermore, among African American, Hispanic, male and low socio-economic status (SES) student subgroups, significant associations were found between relationship quality and English Language Arts achievement. Among African American, female and low SES student subgroups, significant associations were found between relationship quality and mathematics achievement. The results of this study suggest that positive teacher-student relationships are associated with and may contribute to positive academic outcomes for vulnerable students.