Background: Advanced age is a known marker of vulnerability, but frailty is an independent predictor of poor outcomes in critically ill patients. The clinical frailty score (CFS) facilitates rapid assessment, aiding prognostication, care improvement, and resource allocation, particularly in resource-limited intensive care units (ICUs). Materials and methods: A prospective observational cohort study was conducted from April to September 2023 at a tertiary care ICU. The study included 166 patients aged ≥50 years with ICU stays longer than 48 hours, excluding those with contraindications for care escalation. Data were collected on demographics, Clinical parameters, and scoring systems including acute physiological and chronic health evaluation II (APACHE-II), sequential organ failure assessment (SOFA), Charlson comorbidity index (CCI), and CFS. Predictive analyses were performed using receiver operating curve (ROC) curves, cut-offs, and logistic regression. Results: The median age of patients was 65 years, with an APACHE-II score of 18 and a CFS of 4. In-hospital mortality was 46.4%. The CFS outperformed other scoring systems in predicting both in-hospital mortality [Area under the receiver operating characteristic curve (AUC-ROC) 0.73] and net negative outcomes (AUC ROC 0.75). Frailty (CFS ≥6) was present in 39.75% of patients, with each unit increase in CFS associated with a 41.8% higher odds of mortality and a 50.7% higher odds of net negative outcomes. The optimal CFS cut-offs were 4 for 80% sensitivity and 6 for 80% specificity. Conclusion: The CFS is a practical and reliable tool for predicting ICU outcomes, outperforming traditional scoring systems. It supports improved decision-making and resource allocation. Further multicenter studies are necessary to validate its broader use in critical care practice.