This study investigated whether students' gender, prior achievement, and socioeconomic status (SES) moderated the magnitude of teacher expectation effects on students' English-as-a-foreign-language (EFL) achievement. A sample of 30 university teachers and 845 first-year undergraduate students from EFL classrooms participated in the study. Data on teacher expectations, student demographic features, and students' EFL scores in standardized tests before and at the end of the school year were collected and analysed via hierarchical regression analysis. The results showed that in EFL classrooms, 1) teacher expectations had significant effects on students' EFL achievement; 2) the magnitude of teacher expectation effects did not vary in line with student gender or prior achievement; 3) lower SES students were more susceptible to teacher expectation effects than higher SES students. Implications for teacher expectation theories and EFL education are also discussed.