The present study explored the contribution of English as a foreign language (EFL) teachers' perceptions of their learners' achievement to their goal-orientations. It also examined the relationship between their goal-orientations and organizational commitment via correlational analysis. The third aim of this study was to investigate the determinants of EFL learners' success/failures based on EFL teachers' viewpoint via semi-structured interviews. To achieve these objectives, 90 English as a foreign language (EFL) teachers from different foreign language institutes of Mashhad, Iran took part in this study. They were asked to complete three questionnaires: "Perceptions of teacher, student, and family factors influencing student performance," "Organizational Commitment Questionnaire" (OCQ), "Achievement goals for teaching." Findings via correlation analysis indicated that mastery goal orientations had a positive relationship with teachers' organizational commitment. In addition, among teachers' perceptions of their learners' achievement, findings indicated that student-related factors had a high correlation with mastery goal-orientations. Moreover, results from interview proved that EFL teachers perceived teacher-related factors as the main cause of learners' success or failures. Findings are discussed with respect to their implications for both theory and teacher education.