Findings of a study that examined teachers' personal reasons for resigning are presented in this paper, which develops a model of teacher persistence. Interviews were conducted with 57 teachers who resigned from primary schools, and various regional and Head Office positions with the New Wales (Australia) Department of School Education during the 1991-92 school year. Findings suggest that teacher resignation results from teachers' reaching a critical point in their attitude toward teaching. Teacher attitudes toward teaching are influenced by the lack of teacher input for change, commitment to change, and support. The attitude toward teaching is shaped by a complex interplay of many factors, some of which are out of the control of teachers, schools, departments of education, and governments. The appendix contains the interview schedule, three figures, and two tables. (Contains 18 references.) (LMI)