ÖZET
In the current study, conducted to determine the unethical behaviours of teachers based on the opinions of school administrators and colleagues, a phenomenological design was employed. The sample comprised various districts in Istanbul, an online form was used to collect data, and answers were sought to the research questions posed by the researcher. The data obtained were coded within the framework of descriptive analysis and analysed according to categories and themes. The unethical behaviours of teachers were examined under three themes: economic return, educational/instructional processes, and personality traits. According to the findings, teachers exhibit unethical behaviours within the context of private tutoring, financial gain, communication problems, neglect of duty, negative attitudes towards stakeholders, pressure, bullying, lack of competence and understanding, and character. Moreover, the noteworthy unethical teacher behaviours included exploiting students for financial benefit, abusing rights such as medical reports and permits, causing debts for stakeholders, discrimination towards students and parents, using students and the school for personal interests, maintaining relations with administrators to obtain privileges, and acting contrary to scientific rules.