Teachers play a vital role in shaping the lives of our children. In Australia, the teaching work force is experiencing a teacher shortage especially in particular subject areas of science, technology, engineering and mathematics. Teacher retention rate is decided by teachers' outflow i.e. teachers permanently leaving the profession prior to retirement. This research uses the Staff in Australia's Schools 2010 data set as the data base to formulate a logistic regression model of teacher outflow, which enriches the quantitative research into Australian teaching work force planning.