lntroduction: Although hereditary breast cancer usualy arises as the consequence of BRCA /2 deleterious mutations, a large portion of hereditary suspectibility still remains unexplained. Under the polygenic model of inheritance, TP53 and NBS1 where shown to contribute to hereditary breast cancer. NBS1 657Del5 mutation increases the risk for breast cancer three times while mutations in TP53 exon 8 increase the risk for early-onset breast cancer. Since mutations in BRCA1/2 can't explain the whole range of hereditary predisposition, we aimed to investigate the presence of NBS1657del5 and TP53 exon 8 mutations in hereditary breast cancer in Serbia.