Numerous studies have established that teaching can be a stressful profession and that stress may affect career motivation and diminish effectiveness and job satisfaction of many loyal and gifted teachers. Van der Westhuisen (1991) observes that the increasing demands made on the schools and teachers have led to an alarming escalation of stress and professional burnout as career risks for those in the teaching profession. A major concern with occupational stress in the teaching profession is that prolonged experience of stress can precipitate both mental and physical ill-health (Walker & Cole, 1989:28). The widespread concern regarding occupational stress in teaching has led many researchers to focus on this area. Furthermore, there has been an increasing recognition of the link between mental and physical health and occupational stress, and indeed concern to improve the working lives of teachers (Williams & Gersch, 2004). This sought to investigate the sources of occupational stress amongst primary school teachers. The sample consisted of 168 teachers from primary schools in KwaZulu Natal province, South Africa. Data were collected using a questionnaire. The study reveals that teaching stressors which the teachers found stressful, in order of most to least stressful, were curriculum changes, work load pressures, job insecurity, poor relationship with colleagues, reward and recognition, learners discipline problems, poor rapport with management and role ambiguity. In terms of factors associated with teacher stress, the results showed that a combination of internal and external factors were associated with teacher stress. In terms of internal factors, organisational stressors and classroom stressors were associated with teacher stress. In terms of external stressors minimal general life stressors were also found to be associated with teacher stress. The areas which teachers viewed as most stressful were policy changes, timework load pressures and classroom discipline.