The aim of our study was to evaluate whether cardiovascular disease risks seen in adults with polycystic ovary syndrome (PCOS) develop in adolescents with PCOS using conventional Doppler echocardiography (CDE) and tissue Doppler echocardiography (TDE) or not. The other aim was to investigate the association of paraoxonase-1 (PON-1) level with cardiovascular parameters. 30 PCOS patients and 30 control patients were included in the study. All patients were evaluated with TDE and CDE. Paraoxonase-1 levels of both groups were studied. In CDE study, myocardial performance index (MPI) was higher in the PCOS group than in the control group (0.54 +/- 0.11, 0.50 +/- 0.12, p = .049, respectively). In the TDE study, early diastolic myocardial velocity (E)'/late diastolic myocardial velocity (A ') was lower in PCOS group than in the control group (2.07 +/- 0.08, 2.44 +/- 0.10, p = .008, respectively). PON-1 was higher in PCOS group than in the control group (26.81 +/- 3.05, 18.68 +/- 1.18, p = .011, respectively). Cardiovascular disease risks, which are among the long-term complications of PCOS, seem to begin from the early stage of PCOS. The high PON-1 level was thought to increase in response to increased oxidative stress in PCOS.Impact statement What is already known on this subject? Polycystic ovary syndrome (PCOS) is one of the most commonly seen endocrinopathy in the adolescent age group. PCOS has detrimental effects on the cardiovascular system in the adult population which is reported in many studies. What the results of this study add? The result of this study showed that cardiovascular effects, which are among the long-term complications of PCOS, seem to begin from the early stage of PCOS. And also, serum paraoxonase-1 level increases in response to the oxidative stress in the adolescent with PCOS.