Conflicting opinions have been expressed in the world literature over the last 15 years about the value of radiological techniques in breast cancer diagnosis. We reviewed 111 breast cancers which we diagnosed between 1971 and 1985, in unselected patients, by the combined use of palpation, thermography and mammography, complemented, since 1980, by diaphanoscopy. Considerable clinical experience is necessary to interpret both mammograms and thermograms. Each of these approaches, when rated independently, has a very high false negative rate ranging from 41% for clinical examination to 32% for mammography. In cases which are not clinically obvious, diaphanoscopy ''retrieves'' the most cancers, with thermography a close second (definitely malignant in 35% of the cases over the whole age range). Mammography comes third and its efficacy drops to 12.5% in premenopausal women. However, by combining this information with the one derived from anamnesis, the ACDTM scoring system gives us a false negative rate - before biopsy - of 5.5% and a false positive rate of <1%. This approach also drastically reduces the number of unnecessary biopsies.