A cross-sectional survey was conducted among nurses working in a general hospital in Lagos to determine their knowledge, attitude and practice regarding breast cancer. A self-administered questionnaire was used to investigate knowledge of symptoms, methods of diagnosis and use of cancer screening methods. Two hundred and four nurses out of 280 participated in the study (73% response rate). Knowledge about symptoms, methods of diagnosis and self-breast examination was generally very good. However, only 30% had had a clinical breast examination and 8% a mammogram within the past three years. Use of cancer screening methods was significantly associated with knowledge of the subject (p = 0.03). Twenty-eight percent did not know how to estimate the risk of cancer and 61% believed they were not at risk. Nurses possess adequate knowledge about breast cancer but they need more information on cancer risk estimation.