The study aims to develop an instrument for research on teacher self-management in the school organization. In this paper, teacher self-management is conceptualized as a self iterative process which comprises five stages; namely, (i) the Environmental Analysis Stage, (ii) the Planning and Affiliating Stage, (iii) the Developing and Directing Stage, (iv) the Implementing Stage, and (v) the Evaluating and Monitoring Stage. Based on this conception, the instrument developed consists of five subscales. The developed instrument was field tested in 63 schools including 1,183 teachers. The analysis showed that the estimated reliability and the predictive and construct validity of the instrument were satisfactorily high. It is hoped that the instrument may provide a basic tool for related empirical studies and for understanding of teacher's self-management practices in school. Copyright © 1998 Taylor & Francis Group, an informa business.