Background: Hyperandrogenism is the basic indicator of polycystic ovarian syndrome (PCOS) and a key factor in its pathological processes. Patients with PCOS have higher testosterone levels along with a decline in the estradiol/testosterone ratio, which may indicate an aromatase dysfunction. The aim of the study:Investigating the expression levels of CYP19A1 and lncRNA-CTBP1-AS in the granulosa cells (GCs) of women with and without PCOS. Materials and methods: We compared the expression levels of CYP19A1 and lncRNA-CTBP1-AS in granulosa cells from 16 PCOS patients and 20 controls who underwent assisted reproductive technology (ART) treatment at the Center for Human Reproduction and IVF (Rostov-on-Don, Russia) using quantitative real-time PCR. Results: We observed a significant downregulation of CYP19A1 expression in the GCs of PCOS patients, with expression levels approximately 4.7 times lower compared to the control group. Furthermore, we found a positive correlation between CYP19A1 expression and the E2/T ratio in PCOS patients. Conversely, PCOS patients exhibited a remarkable upregulation of CTBP1-AS expression in their GCs, with levels up to 23 times higher than those in the control group. Importantly, we also identified a significant negative correlation between the expression level of CTBP1-AS and CYP19A1 in the GCs of PCOS patients. Conclusion: Our results indicate a potential regulatory role of CTBP1-AS in CYP19A1 expression and suggest its involvement in the pathogenesis of PCOS