The aim was to describe cancer detection method and frequency of screening mammography in women undergoing breast cancer surgery in 2000.Patients undergoing breast cancer surgery were identified through an institutional database. Charts were reviewed to determine presentation at time of diagnosis. Presentation was coded “palpable” if the woman presented with a breast complaint or if a new mass was detected on examination versus “screening” if detected on screening mammogram.Five hundred ninety-two breast cancers were identified: 57% presenting by screening and 43% palpable. Cancer was more likely to present as palpable in patients with no previous screening mammography compared with those with previous mammography (67% versus 39%; p = 0.0002). Patients with palpable presentation were younger than those with screen-detected cancer (mean age 57 versus 62 years; p < 0.0001).Despite the frequent use of screening mammography, 43% of breast cancers presented as a palpable mass or otherwise symptomatic presentation.