Ovarian cancer remains one of the most common causes of death from gynecological cancer in women world-wide. As is known, the course of ovarian cancer depends on many factors, including genetic and epigenetic disorders. MicroRNAs are currently considered one of the most promising prognostic and diagnostic markers for solid tumors. The purpose of this work was to investigate the DNA methylation level of miR-663a and miR-663b in 25 paired tissue samples from patients with an established diagnosis of ovarian cancer and various histological and clinical characteristics by MS-HRM method. Our results indicate a lower frequency of miR-663a methylation in ovarian tumor tissues (0.09% ± 0.01) compared to histologically normal tissues 0.16% ± 0.01 (p = 0.01). However, an analysis of the miR-663a and miR-663b microRNA gene methylation level in patients with different clinical parameters, including the stage of disease development, the degree of cell differentiation, the occurrence of distant and regional metastases, as well as therapeutic pathomorphosis, not identify statistically significant differences in the methylation levels of these mi-croRNA genes with any of the clinical characteristics, p > 0.05. Thus, our results indicate a potential role of aberrant methylation of the miR-663a microRNA gene in ovarian cancer carcinogenesis. However, additional researches on larger sample sizes are needed to confirm the results obtained.