This study sought to compare Iranian EFL teachers regarding their ethical beliefs at Iranian English language institutes and universities. To this end, first, the grounded theory method was used to conduct some interviews with 40 EFL teachers (20 male, 20 female). They were randomly selected from about 140 teachers working at institutes and universities in Fars province, Iran. After coding the obtained data, some categories were recognized, a model was designed, and exploratory factor analysis was conducted. The results confirmed the existence of social, collaborative, emotional, and managerial impacts. Then, a questionnaire was designed and developed based on grounded theory procedures, literature results, and the results of the qualitative studies. 140 EFL teachers filled it out and then the collected data underwent both descriptive and inferential statistics. The obtained results indicated that there was a significant difference between teachers regarding their ethical beliefs in universities and institutes. Moreover, it was revealed that the male and female teachers were significantly different. The mean scores of the female teachers and the male ones are 79.2500 and 75.2500 respectively. The findings of the current study can be useful for teachers, educators, teacher trainers, policymakers, and evaluators to make appropriate decisions and judgments. Manuscript profile