In 2003, the revised American Cancer Society guidelines recommended that breast self-examination (BSE) be optional. Of 822 women diagnosed with breast cancer in our hospital from 1994 to 2004, sixty four (7.7%) were 40 years of age or younger. Forty four (68.7%) of these young women discovered their breast cancers on BSE, 17 (18%) by mammography, and 3 (4.7%) by clinical breast examination by medical professionals. Of 758 women over 40 years of age diagnosed with breast cancer, 382 (49%) discovered their cancer by mammography, 278 (39%) by BSE, and 98 (14%) by a clinical breast examination. Lymph node metastases in the older women was one-half that in the younger women (21% versus 42%), and a higher percentage of younger women presented with more advanced disease. In response to increasing breast cancer in young women under 41 years of age, encouragement of proper breast self-examination is warranted and should be advocated.