The BRCA2 mutations are implicated in a high percentage of hereditary breast cancer cases. We report a novel mutation in a Spanish breast cancer family. We analyzed DNA samples of the proband and of the living first and second degree relatives. Exon 11 of BRCA2 gene were screened by the protein truncation test and direct sequencing. We identified a novel mutation, 6857 delAA, in three affected women, diagnosed of breast cancer at 29, 51 and 45 years of age, respectively, and in a healthy male. The BRCA2 mutation seems to be implicated in the development of early-onset breast cancer cases in this family. Identification of this novel mutation adds to the information on BRCA2 gene in hereditary breast cancer in Spanish population.