The present study was conducted to investigate the relationship among three important teacher variables and studentsâ L2 achievement. To this end, 105 high school EFL teachers from Shiraz and Hamadan were asked to fill out three sets of instruments: the reflective teaching instrument, (Akbari, Behzadpour & Dadvand, 2010), the Attitudes and Beliefs on Classroom Control Inventory (Martin, Yin, & Baldwin, 1998), and the Strategy Inventory for Language Learning (Ardasheva & Tretter, 2013). Also, the scores of the English final exams of 2673 third-grade high school students were collected. The results of Pearson Product Moment Correlations revealed that there was a significant correlation between the above-mentioned three teachersâ variables and their studentsâ L2 achievement. The results also showed a significant difference between male and female teachers in the degree of perceptions of LLSs, while no significant differences were found between the two genders regarding their classroom management orientations and reflection. Moreover, running multiple regression analysis, it was revealed that among the teachersâ variables, reflection was the strongest predicator of studentsâ L2 achievement. Finally, based on the results of this study, some practical implications for maximizing studentsâ L2 achievement in English language classrooms are presented.