The problem of the correlation between reproductive disorders and metabolic syndrome (MS) is well known, but data on the frequency and nature of these disorders among adolescents are extremely limited. The aim of the study: is to determine and analyze the frequency and structure of menstrual disorders in adolescent girls on the background of metabolic syndrome, as well as to study the correlation of these disorders with possible reproductive health disorders in the future. Materials and methods. To achieve this goal, a retrospective analysis of randomly selected 2,000 outpatient medical records (primary registration form № 025/o) of girls aged 10 to 18 years was performed at the Sumy Regional Clinical Perinatal Center from 2011 to 2021. The menstrual cycle was assessed according to the FIGO 2018 classification. Pathological menarche was defined as early (up to 10 years) or late (after 15 years) onset of menstrual function. Polycystic ovarian syndrome (РCOS) was diagnosed according to the Rotterdam criteria (2003): oligo‑ or anovulation (≤ 6 menstrual periods per year); clinical or laboratory hyperandrogenism (hirsutism/acne) and/or hyperandrogenemia (increased levels of free testosterone in the blood); polycystic ovaries during transvaginal ultrasound (≥ 15 follicles 2–9 mm in size in each ovary). Results. The results showed that in adolescent girls with overweight and MS, the frequency of menstrual dysfunction was observed in 71.1% of cases. Moreover, the most common variant of menstrual disorders in this category of patients was oligomenorrhea (60.0%), and the frequency of its manifestations was directly dependent on overweight degree. It was found that almost 82% of girls with confirmed MS had a high risk of developing polycystic ovarian syndrome (PCOS) in the future. Conclusion. It was found that the incidence of obesity in children and adolescents in the population was 27.1%, and the incidence of menstrual syndrome among children and adolescents with obesity was 41.5%. A significant proportion of adolescents with menstrual syndrome had menstrual irregularities – 71.1%, which was significantly higher than in healthy girls – 19%. Among menstrual disorders in girls with menstrual syndrome and obesity, oligomenorrhea prevailed (60.0% and 52%, respectively). Moreover, the frequency of oligomenorrhea was significantly affected by the degree of obesity. Almost 82% of girls with confirmed menstrual syndrome had at least two of the three criteria, which put them at high risk for developing polycystic ovarian syndrome in the future.