“Breast cancer is every women‟s risk” Cancer phobia is a prevalent condition and cancer of the breast is highly threatening women in any culture because breast is a symbol of sexuality and feminity. For more than 30 years breast cancer has been the most prevalent, the most feared, and the malignant disease with the highest mortality rate in women. Aim of the study-A study was conducted to assess the knowledge, attitude and prevalence of risk factors on breast cancer at Vellanur Village, Thiruvallur District, 2010 – 2011. The objective of the study was to assess the knowledge, attitude and prevalence of risk factor on breast cancer. Methodology-The study was conducted by adopting a descriptive research design. 200 samples who have fulfilled the inclusion criteria were selected by using non probability purposive sampling technique.Structured interview questionnaire was used to assess the knowledge and prevalence of risk factors on breast cancer. Both descriptive and inferential statistics were used to collect data collected from the samples. Result-The analysis revealed that the mean score of knowledge on breast cancer among women was 15.24 with S.D 5.07 and the mean score of risk factors was 2.35 with S.D1.72. The calculated „r‟ value was -0.342 which shows a negative correlation and statistically significant at p<0.01 level. This indicates that when the knowledge of women on breast cancer increases the risk factors on breast cancer decreases.Hence the null hypothesis H02 that stated that there is no significant relationship between knowledge and prevalence of risk factors on breast cancer was rejected.Conclusion-The analysis revealed a positive correlation (r = 0.338) at p<0.01 level of significance between knowledge and negative correlation between knowledge and prevalence of risk factors.