Drawing upon appraisal-theoretical framework (Frenzel, 2014), this study aimed at examining the antecedents of pleasant and unpleasant emotions experienced by English as a foreign language (EFL) teachers in Iran. Results of semi-structured interviews with eleven EFL teachers teaching in private language institutes showed that positive interaction with students, motivated students, and students' progress were the most frequently mentioned antecedents of enjoyment. For pride, positive feedback from students and students' progress were identified as the key antecedents. For anxiety and shame, inability to answer students' questions was the key antecedent, while shame was additionally triggered by responsibility for student failure, and anxiety was additionally triggered by class observation by supervisors, and lack of preparation. For anger, disciplinary issues, lack of student commitment to tasks and homework, and having to explain a topic to students several times when they do not understand were identified as the key antecedents. Demotivated and uncollaborative students were identified as antecedents of boredom. In the end, the findings were discussed and pedagogical and research implications were suggested.