Carriers with germline breast cancer 1/2 gene mutations (BRCAm) are likely to develop ovarian cancer (OC). Therefore, identifying these mutations may enable individualized therapy for OC and preventive measures to reduce OC risk in BRCAm carrier families. Thus, we investigated the prevalence of BRCAm in OC patients from Yunnan Province in Southwest China. In total, 674 unselected OC patients were enrolled and tested for BRCAm via next-generation sequencing. Data on clinicopathological characteristics and personal/family history of cancer were collected. The prevalence rates of pathogenic/likely pathogenic BRCAm were 26.6% overall, 20.8% among BRCA1m carriers, 5.5% among BRCA2m carriers, and 0.3% among carriers of both BRCA1m and BRCA2m. The most common pathogenic mutation in the BRCA1 gene was c.5114T>C (n = 9). The number of BRCAm carriers was significantly greater among patients with serous cancer, a personal tumor history, a family history of hereditary breast and ovarian cancer (HBOC)-related tumors, and bilateral tumors. The most common pathogenic mutation in this cohort was c.5114T>C (n = 9) in BRCA1. The prevalence and spectrum of BRCAm in OC patients from Yunnan Province are different from those in other groups. BRCA status testing is advised for all OC patients, particularly those with a family history of HBOC.