A non-randomized controlled trial was conducted in two family medicine centers. The objectives were to evaluate whether or not a systematic prescription by family physicians of a screening mammography to women aged 50 to 69 belonging in majority to a disadvantaged socio-economic group, would permit to reach at least 60% of them and to explore which factors were associated with compliance to the prescription. The experimental intervention consisted in the prescription by the family physician of a mammogram to those patients found eligible for the screening procedure irrespective of the reason for encounter. A total of 468 of the 870 women who consulted a physician during the study period were eligible for a screening mammography. In the experimental group, the mammography prescription rate was 89% for eligible women. At the end of the study, 58.8% (95% Conf. Int.:51.9%-65.7%) of the women in the experimental group and 13.4% (95% Conf. Int.:9.4%-17.4%) of those in the control group had passed a mammography (p