This chapter provides an overview of clinical care for patients at risk for or with mutations identifying them as having hereditary predisposition to colorectal cancer including Lynch syndrome (LS) and familial adenomatous polyposis (FAP). It also describes what has been learned from psychosocial research about the motivations for and uptake of genetic counseling and testing and the barriers to such care. The chapter provides data on psychological distress among family members and family communication and raises arguments about optimal ways to inform relatives about the presence of a deleterious mutation in the family. New methods of universal tumor screening to detect mutations in less heavily affected families are discussed, as are screening recommendations for both children and adults with hereditary colorectal cancers. The importance of also screening for endometrial and other related cancers and conditions and the psychological burdens of lifelong vigilance and complex medical care are reviewed.