In the current study a multi-dimensional scale that measures teacher autonomous behaviour is presented. The scale is applicable across the following educational sectors: primary education, secondary education and vocational education. Based on an elaborate literature study, four theoretically relevant dimensions of teacher autonomous behaviour were derived. Psychometric characteristics of the instrument (note that the terms "scale" and "instrument" are used interchangeably in this article) were tested among a sample of Dutch teachers working in primary, secondary and vocational education (N = 1111). The validity of our instrument was tested in several ways. First, by performing confirmatory factor analysis, we tested the factorial structure, which confirmed the hypothesised four dimensions: (1) primary work processes in the class; (2) curriculum implementation; (3) participation in decision making at school; (4) professional development. Thereafter, we calculated the scale's reliability, which appeared to be excellent. In addition, we tested for measurement invariance by cross-validating the study in the educational sectors mentioned above. Also, the convergent, divergent and predictive validity was investigated. Teacher autonomy appeared to predict workplace learning, more specifically experimenting, reflecting and school development. Finally, we investigated whether transformational leadership can facilitate teacher autonomy, which appeared to be the case. The results empirically confirm the four dimensions of teacher autonomous behaviour, which we derived from theory, and offer solid proof of the psychometric properties of our instrument. The instrument can be used by school leaders and policy makers to monitor autonomous behaviour. More generally, the development and use of this instrument helps us understand teacher autonomous behaviour and teacher professionalism.