A computerized procedure for screening of etiological factors over cancer sites has revealed some interesting differences between patients with thyroid cancer and those with other types of cancer or with non-neoplastic diseases. This screening procedure utilized approximately 22,000 epidemiological interviews on patients admitted to Roswell Park Memorial Institute from 1957 to 1965. Patients with thyroid cancer reported seven of 15 specific complaints or pathologic conditions, as well as tonsillectomies, more frequently than did patients in the comparison series. An excess of Jewish patients occurred in the thyroid cancer group, and the sex ratio of these patients differed from that of non-Jewish patients. Statistical analysis of these differences indicates that they are significant and suggests that further medical investigation be carried out.