The contribution of mammography to the diagnosis of breast cancer was examined in 5080 patients with various breast symptoms. There were 562 breast cancers within this group. The sensitivity of mammography was 88%. Only 18 cancers were detected by mammography alone, and of these 3 were in the other breast. 7 of the remaining 15 cancers had clinical signs which would have been pursued to open biopsy in the absence of mammography. Clinical examination is of paramount importance in the management of patients with symptomatic breast disease. Mammography is most useful when applied in specific situations rather than to screen every patient with breast symptoms.