Objective — to investigate the distribution of BRCA1 and BRCA2 genotype and allele frequencies in healthy women and patients with ovarian cancer (OC) and to determine the contribution of the BRCA1 and BRCA2 genes to the development of main types of the disease, as well as the impact on the course of and treatment efficiency for this disease. Subject and methods. A total of 208 OC patients treated in the Andizhan Regional Oncology Center in 2008 to 2015 and 80 women who were their closest female relatives were examined. Results. The 208 patients examined were found to have 5 out of 8 BRCA1 and BRCA2 gene mutations: 4153delA, 5382insC, Cys61Gly, 2080delA and 3819delGTAAA, which amounted to 11%. The prevailing mutations in all the patients with OC were 5382insC (BRCA1) and BRCA1_4153delA in 8.7 and 2.9% of cases, respectively. The mutation 5382insC in the BRCA1 gene was detected in 2% of the 80 healthy relatives. Conclusion. The paper provides data from the study of the contribution of mutations in the BRCA 1 and BRCA 2 genes to the development of hereditary forms of OC. The detected mutations have an unfavorable prognosis, and the statistically significant risk for OC is very high in first-degree female relatives. This is confirmed by the following investigations studying the risks: RR was 8.9567 with p=0.0305; OR was 9.8216 with p=0.0266.