Background: The most common approach to estimating the presence of oxidative stress in vivo is by measuring the end product of lipid peroxidation such as 8-iso-Prostaglandin F_2α. Measurement of 8-iso-Prostaglandin F_2α is referred to as the gold standard of oxidative stress determination by the Biomarkers of Oxidative Stress Study (BOSS). Due to known association between oxidative stress and diabetic nephropathy, the 8-iso-Prostaglandin F_2α compound is being investigated as an early marker of impaired renal function in diabetic patients. Objective: The aim of this research was to analyze the level of 8-iso-Prostaglandin F_2α on type 2 diabetes mellitus patients with the increasing duration of diabetes mellitus and its correlation with eGFR and UACR value. Materials and Methods: Samples were divided into two groups, which was type 2 diabetes mellitus patients (n=48) and non-diabetes mellitus subjects (n=13) at Pasar Minggu Community Health Center. Urinary 8-iso-Prostaglandin F_2α level was measured by ELISA and eGFR ​​value was calculated using CKD-EPI equation. All measurements were done in 2016 and repeated in 2017 on the same subjects. Results: The mean difference of patient’s urinary 8-iso-Prostaglandin F_2α in 2016 and 2017 was found significant (p=0.004). Spearman’s Rho correlation test showed the correlation between urinary 8-iso-Prostaglandin F_2α and eGFR value (r=0.192; p=0.190) and UACR value (r=0.430; p=0.002). Conclusion: There was significant difference at urinary 8-iso-Prostaglandin F_2α level with the increasing duration of diabetes mellitus. In addition, there was a significant positive correlation between urinary 8-iso-Prostaglandin F_2α and UACR value, but no correlation with eGFR value.