Background: Renal obstruction evaluation by X-Rays and CT scan is harmful and causes ionization in the body. That's why we find out the Diagnostic Accuracy of Doppler Ultrasound by doing it in our population for the Accurate and Early Detection of RI, especially in Renal obstruction. Objectives: To compare the resistive index of the renal artery in obstructive and non- obstructive kidneys by Doppler ultrasound. Methods: Comparative study design was used for this study. 162 patients are taken as sample size from different hospitals (DHQ Joharabad and Gillani Center, Lahore). The duration of the study was 3 Months after the approval of synopsis. Sampling technique used was Convenient Sampling technique. Date collected with the help of questioner and analyzed by using SPSS 22 mean, standard deviation, frequency distribution, and t-test. Results: The mean score value of the resistive index in non-obstructive kidney group was 0.63 ± 0.02. The minimum score value was 0.60, and the maximum score value was 0.66. In obstructive kidney group, the mean value of the resistive index was 0.77 ± 0.03. The minimum score value was 0.73, and the maximum score value was 0.81. There is a significant difference between these two groups as the p value of the t test statistics is less than the level of significance. Conclusion: It was concluded that calculi obstructive kidney caused prominent changes in the value of the resistivity index as compared to the resistivity index of normal kidney. The effect of obstruction has caused elevation of resistivity index pattern