BACKGROUND Breast cancer is the second major cause of cancer mortality in women and is one of the important public health concerns of modern era. This suggests that the methods for early detection of breast cancer needs to be communicated to the general population. Breast self - examination (BSE) is one of the simplest ways of screening in breast cancer and this study intends to find the knowledge regarding breast cancer and BSE. METHODS This is a cross-sectional study conducted in women of reproductive age group belonging to an urban slum of Chennai. A sample of 170 women above 20 years of age were interviewed randomly using a pretested questionnaire in the local language. Ethical clearance was obtained from the IHEC of the Institution and proper informed consent was taken from the women included in the study. RESULTS In the study, we have identified that majority (84.7 %) of the women had awareness about breast cancer, but only 49 out of 170 were not aware that prevention is possible. Only 38.8 % of the subjects had heard of breast self-examination and among them, only 5.3 % had performed the BSE for cancer screening. Less than 2 % of the study population were fully aware about the procedure. Awareness regarding the disease is significantly associated with factors like age, education, and socioeconomic status. (P < 0.001) CONCLUSIONS Based on the study findings, poor knowledge about BSE and the breast cancer prevention methods was observed in this study suggesting the need to educate the high-risk age groups of women especially in low socioeconomic group. KEY WORDS Breast Cancer, Breast Self - Examination, Mammography, Reproductive Age Group, Cancer Awareness, Cancer Prevention, Risk Factors