We report a family manifesting the cancer-family syndrome in which 11 family members had colonic carcinomas (predominantly involving the proximal colon, in the absence of polyposis), with an average age at onset of 35 years. Three women had endometrial or endocervical cancers. The kindred is notable in that its full evaluation was predicated upon the recognition of features consistent with the cancer-family syndrome in only two sisters. The ascertainment and evaluation of the kindred demonstrates the clinical utility of regarding such criteria (early cancer onset, multiple primary cancers, proximal colonic involvement) as a basis for selecting cases for more thorough family-history evaluation. Although such selection criteria are not pathognomonic for the syndrome, identification of a more extensive family cancer history sometimes enables the initiation of a highly specific cancer surveillance program. Specific attention has been given to the problems of screening patients at risk for the development of proximal colonic cancer, an important feature of the cancer-family syndrome. Innovative operative management is also indicated, such as total colectomy for initial colonic cancer, and consideration of prophylactic hysterectomy for women with colonic cancer (because of the high risk of development of endometrial carcinoma).