During the ten years prior to writing, members of the Department of Gynecology of the Woman's Medical College of Pennsylvania have been conducting a clinical research on the periodic pelvic examination of presumably well women. This research was undertaken for the purpose of determining the value of such examinations in detecting cancer of the uterus, particularly the cervix, in an early and curable stage and in detecting lesions of the cervix commonly believed to predispose to cancer. In 1938 and 1939, we succeeded in interesting the women of Philadelphia in this project. As a result, 1,319 white women, 30 to 80 years of age, presumablywell, volunteered to come for pelvic examination twice a year for five years. Most of the volunteers appreciated the importance of the undertaking as a contribution to medical science as well as of value to themselves. With others it was a matter of passing interest.