Introduction: Breast cancer is the most common malignancy in Indian women second only to cervix cancer. In India the Incidence of breast cancer is 30 per thousand women. Although the etiology is not completely understood, a number of risk factors are related to breast cancer or we can simply say that presence of multiple risk factor may increase the overall risk especially for women with positive family history. Statement of the problems: The present study entitled “a study to assess the knowledge regarding breast cancer among B.sc nursing 1st year students at Era College of Nursing, Lucknow” Objective: To assess the knowledge regarding breast cancer among B.Sc nursing 1 year students,To associate knowledge of B.Sc nursing 1 year students with their selected demographic variables that is age, source of information, religion, type of family and marital status. Research Methodology: In the present study, the non experimental research approach with descriptive research research design was used. B.sc nursing 1st year students were selected through non probability purposive sampling technique from Era College of Nursing, Lucknow. A socio demographic variable and self structured questionnaire was use to collect data. Major Finding Of The Study: Section A:- Major finding regarding demographic variables: The present study reveals that about 92% of the students belongs to the age group of 17-21 years and only 8% of students belong to 22-26 years. Focusing on the source of information, about 50%of students gain information from mass media, 30% of students had gain it from health programme, 11.2% of students had gain the information from family members and 8% of students have gain from friends. According to religion, majority of students belongs from Hindu family (63%), (26%) from Muslim family and (11.2%) from Christian family, according to the type of family, majority of students belongs to the nuclear family (69%) and (39%) from joint family. And according to the marital status, All the students are single in B.Sc nursing 1 year.Section B :-Major finding regarding frequency and percentage distribution of students according to the level of knowledge regarding breast cancer:Findings shows the frequency and percentage distribution of level of knowledge of B.Sc nursing 1st year students regarding Breast cancer. Out of 62 sample around 32.2% of the students had good knowledge about breast cancer and 67.7% of students had excellent knowledge about breast cancer. There is no students who had poor knowledge about breast cancer Section C:- To find the association of knowledge of B.sc nursing 1st year students with selected demographic variables :In the present study, chi square formula is used to find out the association between knowledge with selected demographic variables, the study reveals that there is significant association between knowledge with source of information and there is no significant association between knowledge level with age, religion, type of family and marital status. Conclusion: The study finding revealed the majority of students has excellent knowledge about breast cancer (67.7%) and (32.2%) of students has good knowledge and no student has poor knowledge regarding breast cancer.