It is not known if the behaviour of hereditary breast cancer (HBC) differs from that of sporadic breast cancer (BC). The aim of the present study was to analyze clinical-pathological characteristics in patients with BRCA1/2-mutation associated to BC. These data could be useful in the management of HBC. This study includes 17 patients with BC in whom a germ-line BRCA1/2-mutation was diagnosed. The patients were from 10 different families, and four patients had no family history of BC or ovarian cancer (OC). The study of mutations was with the protein truncation test (exon 11 for BRCA1, exons 10 and 11 for BRCA2) and sequencing (the rest of exons). At diagnosis the mean age was 37 years (28-54). Only 3/17 patients presented with involvement of axillary nodes; no patient was diagnosed with metastatic disease. All cases were infiltrating ductal carcinoma; two of them were medullary carcinoma. Histological grade was available in 13/17 cases, with grade III being the most frequent (12/13). Hormonal receptors were negative in 8/10 patients. The mean follow-up was 129 months (23-223). There were three local recurrences at 17, 108 and 151 months; and two distant relapses at 15 months (complete remission) and 92 months. There were three diagnosed contralateral BC. Hereditary breast cancer has malignant pathological features, but the clinical behaviour may be less aggressive than sporadic breast cancer in the same age group.