Norwegian health care for persons at risk for inherited colorectal cancer is regulated by national legislation on the use of predictive genetic testing and conforms with the international guidelines. This paper from the Norwegian Group on Inherited Cancer, is a consensus between all medical genetic institutions in Norway who handle hereditary colorectal cancer. The recommendations take locally available technology and health care resources into account and are realistic with regard to what can be done within the structure of the Norwegian health service. It gives an update of known genetic syndromes, including colorectal cancer, and indications for remitting patients to genetic examinations. The medical health care is detailed for each genetic group and includes prophylactic surgery and follow-up aimed at early diagnosis and treatment according to international standards. Genetic examinations include a thorough family history verified by medical files for all affected relatives, and comprehensive genetic testing for known syndromes in question. For hereditary colon cancer syndrome (HNPCC), the approach is to screen one tumour in a family member who is an obligate carrier with immunohistochemistry for lack of mismatch gene products, and --if found--proceed to full mutation analysis of the corresponding gene. The clinical geneticists are responsible for coordinating health services to those in need. They also have an obligation to collaborate to present the empirical results of the interventions made.