BackgroundLimited data exists on Charlson's weighted index of comorbidity (WIC) predictability for postoperative outcomes following perforated peptic ulcer (PPU) surgery. This study assesses the utility of WIC and other predictive scores in forecasting both postoperative mortality and morbidity in PPU.Materials & MethodsPatients with PPUs operated between 2018 and 2021 in a Malaysian tertiary referral center were included. Clinical data were retrospectively analyzed for association with mortality and morbidity measured with the Comprehensive Complication Index (CCI). Predictability of WIC and other predictors were examined using area under receiver–operator characteristic (ROC) curve (AUC).ResultsAmong 110 patients included, 18 died (16.4%) and 36 (32.7%) had significant morbidity postoperatively (High CCI, ≥26.2). Both mortality and high CCI were associated with age >65 years, female sex, comorbidities (diabetes mellitus, hypertension, and renal disease), and American Society of Anesthesiologist score >2. Most patients who died had renal dysfunction, metabolic acidosis, lactate >2 mmol/L upon presentation preoperatively. While surgery >24 h after presentation correlated with mortality and high CCI, the benefit of earlier surgery <6 h or <12 h was not demonstrated. WIC (AUC, 0.89; 95% CI, 0.81–0.99) showed similar predictability to Peptic Ulcer Perforation (PULP) (AUC, 0.97; 95% CI, 0.93–1.00) for mortality. PULP effectively predicted high CCI (AUC, 0.83; 95% CI, 0.73–0.93; p < 0.001).ConclusionWIC is valuable in predicting mortality, highlighting the importance of comorbidity in risk assessment. PULP score was effective in predicting both mortality and high CCI. Early identification of patients with high perioperative risk will facilitate patients' triage for escalated care, leading to a better outcome.