Sepsis is a life-threatening multi-organ dysfunction resulting in multiple organ failure. Various indices have been developed to predict outcomes in sepsis. Objective: The objective of this study is to evaluate the predictive value of the Shock Index (SI), Modified Shock Index (MSI), and Age Shock Index (ASI) for determining outcomes in patients admitted to ICU with sepsis. Methods: It is a retrospective observational study conducted at the intensive care unit of Shifa International Hospital Islamabad from January 2024 to June 2024. The data was collected from hospital medical records. After screening, 162 patients were included in this study. Demographic data and Clinical data such as vital signs, laboratory results, and clinical diagnosis were collected at admission in the ICU. Data was analyzed using SPSS v25.0. The p-value ≤0.05 was considered significant. Result: The result of the study has shown that 77 patients (47.53%) were male, 85 (52.47%) were female, and 82 (50.62%) had critical outcomes. For critical outcomes, an SI > 0.7 had a sensitivity of 53.9% and a high specificity of 94.3% but a low positive predictive value (PPV). MSI > 1.3 showed a sensitivity of 19.6% and a specificity of 98.1%, with a PPV of 1.6%. ASI > 0.7 had a sensitivity of 15.9% and a specificity of 93.2%, with a PPV of 0.9%. Conclusion: The Shock Index (SI), Modified Shock Index (MSI), and Age Shock Index (ASI) are more effective at ruling out critical outcomes than predicting them.