A selective screening program for the early detection of colorectal tumors was carried out in the Tel-Aviv area. The criteria for inclusion were based, in part, on relevant epidemiologic data which showed that European- and American-born immigrants were at the highest risk for developing this cancer, followed by Israel-born Jews. The Tel-Aviv area, because of its large elderly population of European origin, has a high incidence of colorectal cancer. Families of patients with colon cancer are known to have an increased risk for developing colon tumors. These relatives were actively searched for, and were, along with the control group, examined by Hemoccult testing and flexible sigmoidoscopy. The color tumor (cancer or adenomatous polyps) rate was 6.3% in the group with a family history of colon cancer, as contrasted to 3.8% in a smaller control group without this history. This increased yield, greater than usually found in an unselected population, emphasizes the economic value of selective screening utilizing relevant epidemiologic data and the family history.