Background: Theories distinguish between student-initiated and teacher-initiated regulation of students' learning activities, or between "strong, shared, or loose teacher control" during the completion of learning tasks. Empirical validations for such distinctions are scarce, however. Aim: The present study aimed at (a) investigating students' perceptions of control behaviours exhibited by their English teachers; and (b) exploring the contribution of different types of teacher control behaviours to students' cognitive outcomes (English Achievement). Sample: The sample comprised 732 English as a Foreign Language (EFL) students studying in three major fields of high school (Mathematics, Natural Science, and Humanities). The participants (16-17 years of age) were selected from third-grade classes of 27 EFL teachers working in 25 high schools of 6 main different geographical regions in the Isfahan province, Iran. Method: To obtain a comprehensive picture of different control types exhibited by Iranian EFL teachers, the control subscales of the two existing questionnaires, i.e., the Questionnaire on Instructional Behaviours (QIB), adapted by Den Brok "et al." (2004) and the Questionnaire on Lesson Activities (QLA) used by Den Brok (2001) were merged to form the Questionnaire of Teacher Control (QTC). The development of this Persian instrument involved several steps: translation and back translation by the researchers, one expert translator, and two EFL teachers; piloting; and a final administration of the questionnaire to the student sample. With respect to the second aim of the study, data regarding students' performances on the Standardized National English Achievement Tests were gathered from local educational offices and schools. Results and conclusion: Statistical analyses supported acceptable reliability and validity of the instrument. A main factor structure with three types of teacher control (strong/high, shared/mid, and loose/low) was found to underlie students' perceptions. The results of multi-level analyses indicated that a relatively large amount of variance was explained by the control variables and student variables, and teacher control had a statistically significant effect on student outcomes. Students' English achievement was lowest when they felt control was their teachers' prerogative, higher when they themselves exerted their own control (low teacher control), and highest under shared (mid) control behaviours.