Oxidative stress is a culprit responsible for the development of acute and chronic kidney diseases. We aimed to establish a working model for the dynamic in vivo assessment of reactive oxygen species (ROS) production in rat kidney. A randomized controlled study was performed in 36 adult male Wistar rats subjected to unilateral urinary obstruction (UUO) via ureteral ligation and compared to SHAM controls. Dihydroethidium (DHE) was injected in the femoral vein and in vivo confocal microscopy was performed in the 2nd, 6th and 10th day, respectively after surgery. Maximal ROS levels elicited by UUO were recorded on the 6th day. However, the absolute difference of the means of DHE fluorescence intensity between UUO and SHAM was the highest on the 10th day. Our working model can monitor ROS production at different time frames and our initial findings suggest that the surgery-related ROS levels decline after an initial increase in the first days, whereas the ones elicited by chronic ligation continue to raise.