The aim of this study is to develop a valid and reliable measurement tool to identify teachers' tendencies towards professional development models. In line with the purpose of scale development, a survey model was preferred. The scale was designed to be applicable to teachers from various disciplines currently working in any institution (preschool, primary, secondary, and high school levels). The study sample comprises teachers working in public schools from various districts. During the scale development process, Exploratory Factor Analysis (EFA) was initially conducted, followed by Confirmatory Factor Analysis (CFA). EFA was performed with data from 408 participants, while CFA was conducted with data from 260 participants. As a result of the analyses, a scale consisting of 4 factors and 31 items was obtained. The sub-factors of the scale were named as "Tendency towards observation-based professional activities, Belief in collaboration with colleagues, Participation in collaborative activities, and Resistance to observation and supervision." The Cronbach's Alpha reliability coefficient of the scale was determined to be 0.94. The relationships between the scale factors were examined by calculating Pearson correlation coefficients. Moderate to high positive and significant correlations were found between the total score obtained from the scale and its factors. The findings revealed that the scale demonstrated a satisfactory level of internal consistency, indicating its validity and reliability. Accordingly, the scale was designated as the "Professional Development Models Tendency Scale."