Early detection of breast cancer has been shown to decrease the mortality rate. Technology continues to evolve to improve the accuracy of detection. In addition, the process of individual risk assessment is evolving, and new factors that affect risk are being identified The purpose of this document is to clarify the rationale for current breast cancer screening guidelines and evaluate the evidence regarding screening techniques. It also focuses on mammography and other detection techniques as screening tools to identify nonpalpable lesions;the use of mammography for diagnostic purposes when a lesion is palpated is addressed briefly.