This two-wave study examined the cross-lagged relations between teacher-student relatedness (student-teacher communication, teacher trust, and teacher alienation) and reading achievement of academically at-risk secondary students (N = 787) in Singapore. Compared with the cohort, these students had lower aggregate scores in a national examination administered at Grade 6. The results of the study showed that teacher trust at T1 (Grade 7) served as a positive predictor while student-teacher communication at T1 served as a negative predictor of reading achievement at T2 (Grade 8), after controlling for reading achievement at T1, gender, and general cognitive ability. Reading achievement at T1 was found to be a negative predictor of all dimensions of teacher-student relatedness, except teacher trust, at T2, even after accounting for the effects of teacher-student relatedness at T1, gender, and general cognitive ability. The results of the study reflect the complexity of the relationship between students' academic achievement and teacher-student relatedness.