Purpose: To examine teachers' views on the corrosive effect of toxic leadership behaviours of school administrators on teacher accountability. Design/Methodology/Approach: The study group of this research, which uses phenomenology as a qualitative research design, was selected using maximum variation sampling method, which is a type of purposive sampling. This group consists of 20 teachers working in 10 public schools in the central district of Isparta. Data were collected from the teachers through a semi-structured interview form. The collected qualitative data were subjected to contextual analysis through MAXQDA software and visualised. The findings show that the majority of teachers reported that toxic leadership has a detrimental effect on teacher accountability. Findings: Toxic leaders, characterised by behaviours such as micromanagement, lack of empathy, and aggressive communication, were found to cause teacher demotivation, alienation, and professional burnout. In addition, toxic leaders erode teacher accountability by creating a negative and insecure organisational climate. Highlights: Toxic leadership behaviours of school administrators are a critical factor that significantly affects teacher accountability. The various dimensions of this impact are as follows: Decreased teacher motivation, psychological safety and job satisfaction, decreased performance and productivity, impeded professional development, stress and burnout. In addition to these, toxic leadership has a negative impact on school climate. A negative school climate leads to a decrease in teachers' willingness to cooperate and be accountable. This can also negatively impact student achievement because lack of co-operation and support among teachers reduces the quality of education. Therefore, it is important for school administrators to exhibit more positive and supportive leadership behaviours to increase teachers' motivation and strengthen their accountability.