The aim of this study was to develop a valid and reliable data collection tool in order to measure the accountability of school administrators. In data collection, Accountability Behavior Scale for School Administrators (ABSSA) was used. Exploratory sequential mixed method design was used in the development of ABSSA. In sample selection, maximum variation method was used in the qualitative stage and simple random sampling was used in the quantitative stage. The data were collected from three different teacher groups working in Erzurum, Turkey in the 2021-2022 academic year. 41 teachers participated in semi-structured interviews, 278 teachers in Exploratory Factor Analysis (EFA) and 223 teachers in Confirmatory Factor Analysis (CFA). Qualitative procedures were followed during the development of the item pool. Content analysis was used to analyze qualitative data. The scale items were developed based on the themes and codes that emerged in the content analysis. The psychometric properties of the ABSSA were investigated using quantitative procedures. EFA revealed a structure consisting of 16 items and four factors, which explained 61.90% of the total variance. These factors were as follows: Accountability towards Students, Accountability towards Teachers, Accountability towards Parents, and Accountability towards Superiors. The structure revealed by EFA was confirmed using CFA. The fit indices of the obtained model were as follows: χ²/sd=1,98, CFI=0.98, NFI=0.96, GFI= 0.90, AGFI= 0.86, RMSEA=0.06, SRMR=0.05. The structure of the scales was confirmed by CFA. The validity and reliability analysis of ABSSA showed that it was a valid and reliable measurement tool with four factors and 16 items.