The value of palpation findings and mammography in 596 patients with primary breast cancer was investigated. The most frequent symptom (86.1%) was the lump. The primary tentative diagnosis came from the patient in 63.4% of the cases, from the physician in 28.9% of the cases, and only after mammography in 7.7% of the cases. False-negative palpation findings and false-negative mammography findings were observed in 9.9% and 5.0% of cases respectively. There was a clear dependence on the tumor stage. Carcinomas that were first diagnosed by means of mammography manifested a five-year survival rate of 82.6% and a recurrence rate of 15.2%. Carcinomas that were first discovered by the patient or the physician reached a five-year survival rate of 67.7% and 70.6% respectively. Here, too, the recurrence rate was higher, at 26.2% and 22.1% respectively. The data show that the carcinomas that were first suspected mammographically were smaller and manifested lymph node metastases more rarely. In order to reduce the number of false-negative findings the physician performing a mammography or assessing X-ray films should himself submit the breast in question to a thorough palpatory examination.