Germline mutations in the BRCA1 gene are causative for a variable number of hereditary breast/ovarian cancers. The data presented in this study are based on genetic analysis of the BRCA1 gene in 49 DNA samples from breast cancer patients with a positive family history. A combination of manual direct DNA sequencing and SSCP analysis was used to screen the entire coding region of BRCA1. Overall 13 variants were detected which included 5 missense mutations, 3 polymorphisms and 5 intronic changes. Further genetic analysis of the 13 variants was carried out using 50 control DNA samples. Our results showed that 12 out of the 13 variants detected in the DNA of the patients group, were also present in the control group. It appears that the Greek Cypriot families studied so far have an unexpectebly low frequency of deleterious mutations in the BRCA1 gene. This is the first report on BRCA1 mutation analysis in Cyprus.