Background: Lumbosacral transitional vertebrae (LSTV) are anatomical variations in the lumbosacral region, often implicated in chronic lower back pain. Accurate diagnosis of LSTV is critical for appropriate clinical management. This study aimed to assess the utility of Sacral Inclination and Lumbosacral Angle measurements in predicting LSTV using magnetic resonance imaging (MRI). Methods: A comparative cross-sectional study was conducted, including 100 cases with confirmed LSTV and 100 controls without LSTV. Sacral Inclination and Lumbosacral Angle were measured on sagittal MRI images. Receiver operating characteristic (ROC) analysis was performed to determine the diagnostic performance of these angle measurements in predicting LSTV. Results: The mean Sacral Inclination and Lumbosacral Angle were significantly higher in cases compared to controls (p < 0.001). ROC analysis revealed that Sacral Inclination had a moderate ability to predict LSTV, with an area under the curve (AUC) of 0.62. The optimal cut-off value for Sacral Inclination was 37.2°, yielding a sensitivity of 85.2% and a specificity of 59%. Lumbosacral Angle demonstrated better predictive capability, with an AUC of 0.85. The optimal cut-off value of 42.8° provided a sensitivity of 83% and a specificity of 81%. Conclusion:Lumbosacral Angle is a more reliable predictor of LSTV compared to Sacral Inclination, demonstrating better diagnostic performance. These angle measurements could be valuable in enhancing the accuracy of LSTV diagnosis, aiding in the clinical management of patients with low back pain. Further studies are needed to validate these findings across diverse populations.