Breast cancer is the commonest cancer among women globally, including Nigeria. Lack of screening and late presentation is major contributory factors to the high morbidity and mortality rates recorded in Nigeria. Culture and religious beliefs have been shown to influence breast cancer screening practice, and type of treatment sought. This study seeks to assess cultural factors and religious beliefs affecting breast cancer screening behavior among Nigerian women. The study population is women living with breast cancer from three major ethnic groups in Nigeria (Hausa, Ibo, and Yoruba) attending six selected health care facilities in Nigeria. Qualitative and quantitative tools will be used to elicit information on breast cancer screening practice, cultural and religious beliefs related to breast cancer screening. Descriptive statistics and Chi-square test will be used to analyse survey data, and thematic approach for qualitative data. The study is expected to provide useful information to plan focused interventions.