Quality mammography with knowledgeable interpretation is now a widely utilized and reliable procedure. It permits clinically occult lesions to be detected and clinically obvious or indeterminate lesions to be managed more intelligently. Abnormal mammographic signs are well defined, as are their differential diagnoses. Thermography of the breast is a younger science than mammography and must mature before its full potential can be realized. It is clear that thermography today cannot be considered an adequate prescreening technique to obviate further examination, as was once anticipated. Used in conjunction with physical examination and mammography it can serve to reinforce suspicions, and the high acceptability of the examination is an impetus to further clarify its role in detection.