Background: Neutrophil-to-Lymphocyte Ratio (NLR) and Platelet-to-Lymphocyte Ratio (PLR) are inflammatory biomarkers that can predict varying degrees of CAD. The primary purpose of this investigation was to assess the relationship of NLR, PLR, and NMR with CAD severity in CA patients. Methods: 100 patients undergoing CA at Dow University Hospital Karachi were assessed for NLR, PLR, and NMR. Underlying risk factors and comorbidities were assessed from the patients' respective blood reports. The CAD severity was evaluated using the Syntax Score (SS). The data was collected from December 2022 to December 2023 and analyzed using SPSS. Results: The Kruskal-Wallis statistics showed a positive link of SS Categories with NLR (p<0.001), PLR (p<0.001), and NMR (p<0.001). The Mann-Whitney U-test displayed differences in NLR (p <0.001), PLR (p <0.001), NMR (p=0.028), and syntax score (p <0.001) within CAD+ and CAD- groups. The ordinal logistic regression evaluation resulted in a significant association of NLR (p=0.004) and PLR (p=0.022) with SS categories, unlike NMR (p=0.120). Receiver Operating Characteristic (ROC) area under curve (AUC) analysis showed that NLR (AUC=0.850) is best at predicting CAD severity in CA patients as compared to PLR (AUC=0.803) and NMR (AUC=0.784). Conclusion: The study's results proved the hypothesis that NLR, PLR, and NMR are independent predictors of CAD severity assessed with Syntax Score. This is the first study that shows that patients can be evaluated for CAD severity using NMR.