Background: There is a lack of consensus about whether the initial imaging method for patients with suspected nephrolithiasis should be computed tomography (CT) or ultrasonography. Material and Methods: This is a Prospective, descriptive and single centre study. A total of 90 patients’ USG and CTU were compared for the presence of calculi in the Department of Radiology, Dr. VRK Women’s Medical College, Teaching Hospital and Research Centre. Sensitivity, specificity, accuracy, positive predictive value and negative predictive value of USG were calculated with CTU as the gold standard. Results: From the 90 sets of data collected, the sensitivity and specificity of renal calculi detection on USG were 53% and 85% respectively. The mean size of the renal calculus detected on USG was 6.8 mm ± 3.8 mm and the mean size of the renal calculus not visualized on USG but detected on CTU was 3.5 mm ± 2.7 mm. The sensitivity and specificity of ureteric calculi detection on USG were 12% and 97% respectively. The sensitivity and specificity of urinary bladder calculi detection on USG, were 20% and 100% respectively. Conclusion: This study showed that the accuracy of US in detecting renal, ureteric and urinary bladder calculi were 68%, 80% and 99% respectively.