A questionnaire survey of 200 doctors who were a sample of the general practitioners of the Bas-Rhin department was carried out. This was in order to ascertain what they knew about cancer of the breast and how they practised medically in this area, what were their doubts and what motivated them to screen for this kind of cancer? The questionnaire was found on the whole to acceptable. The enquiry showed that undoubtedly doctors were in favour of screening for cancer of the breast but were less enthusiastic carrying it out routinely. They also were unaware of ways in which such screening could be carried out (mammography being considered and examination which shows where the cancer was and not as a screening method). Furthermore, there was some confusion between screening and means of diagnosis. Results of this study show that it should be possible to outline the content and means of informing general practitioners about how to screen in order to enable them to participate in the Alsatian pilot campaign for screening for breast cancer.