Objective: Ovarian cancer (OC) is one of the most fatal types of cancer and affects 1%-1.5% of women worldwide. The most common genes causing OC are the BRCA1 and BRCA2 genes. However, improvements in next-generation sequencing (NGS) technologies have allowed for screening of the various genes related to hereditary cancer syndromes. The aim of this study was to evaluate cancer-related gene variations among cases of ovarian cancer. Materials and Methods: The study evaluated 63 cases that were referred to the Marmara University Pendik Training and Research Hospital Genetic Diseases Diagnostic Center between 2016-2021 with a diagnosis of OC for germline variations in 25 cancer-related genes using NGS. Large intragenic rearrangements of the BRCA1 and BRCA2 genes were screened using multiplex ligation-dependent probe amplification (MLPA). Results: The study detected 12 distinct pathogenic variations in the BRCA1, BRCA2, BRIP1, and RAD50 genes in 13 OC cases. Four of the 13 cases involved copy number variations that included at least one exon of the BRCA1 gene. Conclusion: This study detected pathogenic BRCA1 variations to be the leading cause of hereditary OC. The study showed just screening for BRCA1 to reveal the underlying hereditary defect in 76.9% of the cases, which seems higher compared to literature. More studies involving larger cohorts are necessary to figure out the exact frequency of BRCA1 variations in Turkish OC cases.