As a result of the role of teachers’ psychological factors in affecting their performance, there has been a bourgeoning interest in the significance of teachers' constructs in influencing their effectiveness and work engagement. As an attempt to shed more light on the relationships between teacher psychological factors in English as a Foreign Language (EFL) context, the purpose of this study was set to explore the role of teachers’ self-efficacy and their collective efficacy as the predictors of work engagement among Iranian EFL teachers. In so doing, a sample of 168 English teachers completed the self-report scales of the constructs under investigation. Structural Equation Modeling was adopted to test the structural model of the constructs. The results revealed that teachers’ sense of efficacy explained for 23.7 % of the work engagement variance whereas teacher collective efficacy accounted for 10.5 % of the variance in work engagement. It was revealed that although each variable had a unique contribution to work engagement, teachers’ individual self-efficacy was a more powerful predictor of work engagement than their collective efficacy. Based on the findings, important implications can be provided for EFL teacher education programs.