The purpose of this study is to raise the quality of teaching English language and to contribute to the improvement of ELT Teachers profession by investigating the extent to which English teachers at Mugla Sitki Koçman University apply the ethical code towards students during their teaching process. The study was conducted in Preparatory School of English at Mugla Sitki Koçman University. The participants of the study were both teachers and students of the departments concerned. The data gathered from the study were analyzed both quantitatively and qualitatively. To analyze the results of the quantitative data, SPSS (version 20) was used. Classroom observations and interviews were also carried out to support quantitative data. Classroom observations and interviews were analyzed qualitatively. According to the results of quantitative data, it was found that there are significant differences between the views of the students and the teachers of English about the application of those ethical principles such as catering for varied learning needs of diverse learners, dealing considerately and justly with each student and seeking to resolve problems, including discipline according to law and school policy.