The opportunity to intercept a malignant process before it manifests itself clinically is the essence of any screening effort. The usefulness of a properly performed and interpreted mammographic examination in detecting such preclinical lesions in the breast has been documented repeatedly, but perhaps most convincingly in the recently completed evaluation of the Breast Cancer Detection Demonstration Project [1 ]. Furthermore, the results of the 1 963 New York Health Insurance Plan (HIP) study [2] evidenced a reduction in mortality from breast cancer due to periodic clinical and mammographic screening. With such a groundwork, the impetus to screen large populations for breast cancer has been recognized for some time by the medical community and more recently by reimbursement institutions. Following the lead of several states, the recently passed congressional Catastrophic Health Plan provides federal reimbursement for screening mammography beginning in 1990 [3]. Attendant to such opportunities are the increased professional, ethical, and legal responsibilities of the imaging cornmunity. Types of practices vary in this effort as do the medicolegal consequences of such practices. Although “a little knowledge is a dangerous thing,” ignorance of the legal consequences of medical practice may be even more dangerous for the practicing radiologist. This report should serve as a primer for the radiologic community, drawing attention to basic legal considerations affecting the nature of mammographic practice. Statutory and Common Law