Purpose: The purpose of this paper, three-study research project, is to establish and validate a two-dimensional scale to measure teachers' and school administrators' accountability disposition. Design/methodology/approach: The scale items were developed in focus groups, and the final measure was tested on various samples of Israeli teachers and principals. Real-life accountability scenarios, individual work characteristics and performance evaluation were used for the validation. Correlational as well as multi-level statistical procedures were employed. Findings: Confirmatory factor analysis confirmed the two-dimensional structure: external and internal. Study 1 confirmed the convergent validity of the scale vis-à-vis accountability scenarios in teachers' work. Study 2 confirmed its construct validity vis-à-vis related individual work characteristics such as goal orientation, work ethic and conscientiousness, using school principals as participants. Study 3 confirmed the scale's predictive validity vis-à-vis teacher work performance. Research limitations/implications: The scale developed in this study may be used to enhance research on the personal aspect of accountability, contributing to a better understanding of educational systems operating in an accountability environment. Practical implications: The study offers researchers a tool to measure accountability from an individual perspective. The two-dimensional scale developed in this study may help to point out individual differences in teacher accountability disposition. Social implications: The ability to assess personal accountability may contribute to society's concern with school accountability and its effect on educators' work. Originality/value: Educational research in recent years is replete with studies on school accountability, but relatively little has been written on accountability at the individual level of analysis. Few scales exist that measure educators' self-report accountability.