Abstract: Background: Early breast cancer detection can effectively improve treatment chance, survival and quality of life. Health awareness and screening are the main pillars of early detection. Objectives: To compare the pre- and post-intervention knowledge, attitude and practice regarding breast cancer and its early detection. Methods: This is a pre-post-interventional study carried out on 120 women employees voluntarily participated in the breast cancer screening campaign implemented in Mansoura University. Champion's Health Belief Model (HBM) Scale, knowledge questionnaire and breast self-examination (BSE) observation checklist were applied before and after the intervention. Intervention included a lecture, video and brochure containing information about breast cancer definition, magnitude of the problem, risk factors, early detection, signs and symptoms, screening and BSE. Results: The pre-intervention median scores of general knowledge, BSE knowledge and practice were five, three and zero; respectively. Only the general knowledge score is significantly higher in highly educated employees. These scores increased significantly in the post-intervention. The HBM score was 32.85±7.23 in the pre-intervention and significantly increased to 43.73±5.49 post-intervention. Conclusion: Women had poor knowledge in all domains studied. The intervention is effective in raising awareness of women employees about breast cancer and early detection. It may be used as a template for wide scale application in different settings