Cancer is associated with a wide range of hereditary disorders. Recognizing these disorders in cancer patients may be of great importance for the medical management of both patients and their relatives. Conversely, recognizing the fact that cancer may develop in patients already diagnosed with a particular hereditary disorder may be important for the same reason. We have developed a stand-alone interactive computer program, Familial Cancer Database (FaCD), to assist the clinician in making a genetic differential diagnosis in cancer patients as well as in becoming aware of the tumour spectrum associated with a particular hereditary disorder. The program tries to match tumour and non-tumour features observed in patients and their families with any of the more than 300 disorders presently contained in its database and provides a clinical synopsis with literature references for each of these disorders. FaCD is offered free of charge in support of the Familial Cancer and Prevention project of the UICC Cancer Epidemiology and Prevention program. The software is primarily aimed at health care professionals with at least a basic knowledge of clinical cancer genetics, and can be downloaded from the internet at http://facd.uicc.org.