Epidemiologic studies have shown that women who have successfully recovered from breast, uterine, or ovarian cancer have about twice the expected risk of developing colorectal cancer. These high-risk women were entered, therefore, into a large bowel screening program based on fecal occult blood detection, flexible sigmoidoscopy, and colonoscopy, when appropriate. The study group consisted of 183 women and the results were compared with 252 comparison subjects of similar age and ethnic origin. Neoplastic lesions, adenomatous polyps, or cancer were 2.5 times more frequent in the study group. However, for the largest group, women with a past history of breast cancer, the relative risk, adjusted for a family history of gastrointestinal cancer, was 3.0 (P = 0.03). This pilot study confirms the value of continuing to screen these patients, especially those with a positive family history of gastrointestinal malignancies. However, for psychological and administrative reasons, it may be better that their colon screening be integrated into a combined colon, breast, and gynecologic tumor follow-up, and not be part of a separate service.