Breast cancer family history has been known to be one of the main cancer risk factors. Members of high-risk families should be given recommendations which may improve prophylaxis, early diagnosis and treatment. Detection of high-risk families is possible by identification of mutations in cancer susceptibility genes like BRCA1 and BRCA2 as well as by family history showing breast and/or ovary cancer aggregation. In a group of 521 breast cancer patients we identified 26 patients with hereditary breast cancer who fulfilled the following criteria: one more relative with breast cancer, vertical transmission, at least one breast cancer patient affected at the age under 50 years. 8 patients of these developed second primary breast cancer. We also compared the frequency of hereditary cancers in stage I-III with the frequency of respective cancers with negative family history. Hereditary breast cancers were diagnosed less frequently in stage I and more frequently in stage II and III (RR = 0.49, RR = 1.39, RR = 1.62, respectively). Because of importance of family history as well as genetic testing for breast cancer susceptibility genes (BRCA1/2), it is necessary to create a nationwide network of hereditary cancer clinics for proper diagnosis, treatment, and prophylaxis of these patients.