Epidemiologic data suggest that an underlying genetic disposition can be detected in up to 10% of all colorectal cancer patients and autosomal dominantly inherited hereditary non-polyposis colorectal cancer (HNPCC) is the entity most frequently identified. It was described first by A. Warthin in 1895 in "Family G" and is characterized by a predisposition to an early onset of colorectal cancer and other intestinal or genitourinary tumors. We report the case of a 61-year-old woman with five different cancers. Although the strict Amsterdam Criteria were not fulfilled, molecular analysis revealed HNPCC; further genetic testing in the family confirmed that the 36-year-old and so far healthy son had inherited the germline mutation of his affected mother. Genetic testing in clinically suspected HNPCC cases is recommended for patients with colorectal cancer meeting the Amsterdam Criteria. In patients meeting one of Bethesda Criteria 2-7 without meeting the Amsterdam Criteria, germline mutation analysis is recommended only in MSI-positive tumors.