A descriptive study was carried out to explore the beliefs and behaviours of Iranian teachers toward breast cancer and breast self-examination (BSE). A 10% random sample of 8000 teachers working in four central regions of Tehran was selected. Data on beliefs and behaviours regarding breast cancer and BSE were collected by means of a structured questionnaire. In all, 578 women participated in the study. The mean age of the respondents was 37.3 y (s.d.=8.8), and most were married (83%). The majority of the respondents believed that 'Like every other woman I am at risk of breast cancer' (67%) and that 'Family history of breast cancer is a risk factor for breast cancer' (59%). However, only 6% of them reported that they are performing BSE on a regular basis. The most common reasons for not doing BSE and not going for clinical examination were lack of knowledge and the belief that it was not necessary (34 and 36%, respectively). Doing BSE was more frequent in married (P<0.00001), and older (P<0.00001) women. Except for those with a positive family history of breast cancer, there was no association between breast cancer beliefs and almost all other variables studied. The findings suggest that although the majority of Iranian teachers seem to be quite knowledgeable about breast cancer, they need more education on breast cancer and BSE. Since teachers' beliefs and behaviours may have an impact on young females, planning training courses for this group of women is essential.