This study aims to develop a scale to determine the Teachers' Management of Undesirable Student Behaviours. The study to determine the construct validity and internal consistency was carried out in the general screening model. The study groups consist of 822 students (458 for AFA; 364 for DFA) studying at various high schools in the centre and districts of Kirklareli in the 2020-2021 academic year. According to the exploratory factor analysis, it was seen that the scale consists of 3 factors and 21 items. The reliability of the scale was determined from the reliability analyses conducted with the Cronbach Alpha (a) coefficient and McDonald's Omega coefficient. The total Cronbach Alpha ([alpha]) value of the scale is 0.90. As a result of the test, it was understood that all substances are distinctive because the "t" values are significant at the. 001 level. According to the result of the confirmatory factor analysis, all items are significant under the relevant factors. These results show that the Scale of Teachers' Management of Undesirable Student Behaviours is a valid and reliable scale. The scale can be used at the national and international levels to determine teachers' levels in managing undesirable student behaviours. [The publication year (2022) shown on the PDF is incorrect. The correct publication year is 2023.]