Background: Understanding the global prevalence and phenotypic features of polycystic ovary syndrome (PCOS) is important as geographic factors and ethnic variations can significantly alter the clinical syndrome. The aim of this study was to determine and evaluate the luteinizing hormone/follicle-stimulating hormone ratio (LH/FSH) in women with PCOS during therapy on selected endocrine and biochemical parameters. Results: Women with PCOS were included in the study and were classified into two groups: women without therapy (de novo) and women with therapy for PCOS. ESHERE/ASRM criteria that require the presence of two out of three criteria: ovulatory dysfunction, hyperandrogenism, and morphological PCOS detected by ultrasound diagnostics. Electrochemiluminescence immunoassay (ECLIA) was used for FSH and insulin analysis. The enzymatic method was used to analyze the biochemical profile. There was a significant difference between the two groups in terms of the LH/FSH ratio (2.56 vs. 2.41, P=0.043), glucose (6.23 vs. 5.12, P=0.003), insulin (19.21 vs. 7.35, P=0.000), IR (3.22 vs. 1.42, P=0.000), cholesterol (5.97 vs. 4.92, P=0.002), and LDL (3.56 vs. 2.56, P=0.001). The data suggest that patients with PCOS therapy have reduced hyperinsulinemia and insulin resistance. There was a significant correlation between the LH and FSH in the de novo group, as well as the correlation between hormone levels and LH/FSH ratio in both groups. Patients with PCOS therapy have a tendency for normal body weight and reduction of severe obesity compared to patients without therapy. Clinical features such as regular menstrual cycle and the prevalence of acne and hirsutism are not significantly different between groups. Conclusion: PCOS cause irregularities of the menstrual cycle, the appearance of clinical manifestations, especially changes of LH/FSH ratio. Therapy for PCOS contributes to better regulation of endocrine and biochemical parameters, especially in the reduction of hyperinsulinemia, insulin resistance, and reduced LH/FSH ratio.