The efficacy of screening by clinical breast examination (CBE) and/or breast self-examination (BSE) is reviewed using indirect evidence from randomized breast screening trials and that from observational studies. In countries where breast cancer is diagnosed at an advanced stage, screening by CBE with the teaching of BSE as an integral component will probably be effective in reducing breast cancer mortality. However, in technically advanced countries where adequate treatment is given, no screening modality is likely to be sufficiently beneficial to outweigh the harms of screening, especially false positives and over-diagnosis.