Objective Polycystic ovary syndrome (PCOS) is a heterogenous condition and phenotype varies widely depending on life stage. PCOS usually begins at adolescence with reproductive manifestations, proceeding to metabolic complications over time. In this study, we aimed to evaluate the effect of aging on hormonal and metabolic features in young women with PCOS. Methods We recruited 494 women with PCOS (16~39 yrs) and 962 regular cycling heatlhy women as control (16~39 yrs). Anthropometric measurements were obtained and metabolic and hormonal parameters were determined. Glucose tolerance status was assessed by 75 g OGTT. Women with PCOS and controls were divided into 3 groups by age; < 20, 20~29 and 30~39 yrs old. Results In the total PCOS group, age correlated positively with BMI (r = 0.097, P < 0.05), waist (r = 0.140, P < 0.01), fasting glucose (r = 0.143, P < 0.01) and post-load 2 hr glucose levels (r = 0.231, P < 0.001), but there was no significant correlation with total and free androgen levels. In total control group, age was negatively correlated with free testosterone levels (r = -0.139, P < 0.001) and positively correlated with waist (r = 0.071, P < 0.05). Based on age groups, the prevalence of IFG or IGT (9.8, 10.9, 17.2%, P for trend < 0.05), DM (1.1, 2.7, 15.6%, P for trend < 0.05) and metabolic syndrome (16.3, 15.1, 45.3%, P for trend < 0.05) were significantly higher in age over 30 years old compared to the other 2 groups in women with PCOS, but not in controls. Conclusion Metabolic abnormalities worsen during reproductive life in women with PCOS and this may be attributable to the increase in obesity.