Background: Breast cancer is a serious disease with potential high morbidity and mortality. It is the commonest malignancy in women. Approximately one million new cases of breast cancer are diagnosed each year wide world. The aim of this study is to evaluate the effect of breast self-examination training program on knowledge and practice of working women at secondary schools in Assiut and El Menia cities. Material and Methods: The study was conducted in four work places (4 schools) at Assuit and El-minia cities. The equivalent sample included in the study 104 of a group of working women. Three instruments were used for data collection the first tool included self-administrated questionnaire to assess socio-demographic data the second tool to assess knowledge level of the participants related to breast cancer and breast self examination information about cancer breast (pre & post test).Third tool included an observation checklist to assess the practice of the participants related to breast self examination. Two constructive BSE training sessions were carried out, in the form of lectures, group discussions demonstration and re-demonstration.