The study investigated the level of perceived self-determination and selfefficacy of the EFL instructors working in the Anadolu University School of Foreign Languages (AUSFL) in the 2003-2004 academic year. The study also examined the possible relation between instructors’ perceived self-determination and self-efficacy. Forty-nine EFL instructors working in AUSFL participated in the study. Two data collection instruments were used in the study. A survey combining the Work Climate Questionnaire (Deci et al., 2001) and the Teacher Efficacy Scale (Woolfolk & Hoy, 1990) was used to identify the level of perceived selfdetermination and self-efficacy of the instructors. Interviews were then carried out with ten participants chosen considering their levels of self-determination and selfefficacy to explore the perceived self-determination and self-efficacy of the instructors and the possible relation between the two. The results revealed that the majority of instructors perceived themselves to be working in an autonomy supportive environment. Textbook selection, the use of extra materials, teaching methods, and exam preparation were the areas the instructors mostly felt autonomous. However, unmotivated students and heavy workload affected the instructors’ motivation negatively. The quality of relationships between the instructors and the administration also appeared to be influential. As for teacher efficacy, the majority of instructors had high levels of personal and general teaching efficacy. However, no significant relation was found between the levels of self-determination and self-efficacy of the instructors. The results reveal the importance of autonomy support in work settings for teachers, but also the complexity of the factors that influence teachers’ perceptions.