Abstract: Perforated peptic ulcer (PPU) remains a major surgical emergency with persistently high postoperative mortality, particularly in resource-limited private regional hospitals where simple, rapid risk-stratification tools are most needed. This retrospective analytic cohort study evaluated the Boey score (preoperative shock, major comorbidity, and delayed presentation >24 hours) as a predictor of postoperative mortality in 67 patients with PPU who underwent laparotomy at RS Efarina Etaham, Pematang Siantar, Indonesia, between November 2022 and June 2026, using total sampling. Overall mortality was 25.4%. Delayed presentation >24 hours was the most frequent component (94.0%), followed by major comorbidity (61.2%) and preoperative shock (28.4%). Mortality rose steeply with increasing Boey score, from 0% at scores 0–1 to 87.5% at score 3 (chi-square p<0.001; logistic regression OR 57.42 per 1-point increase, 95% CI 9.05–364.13, p<0.001). Receiver operating characteristic analysis showed outstanding discriminative ability, with an area under the curve (AUC) of 0.936 (95% CI 0.873–0.986). The Youden-optimal cut-off was Boey score ≥3 (sensitivity 82.4%, specificity 96.0%), while a cut-off of ≥2 achieved perfect sensitivity (100%) as a screening threshold. These findings confirm the Boey score as a robust, low-cost bedside prognostic tool for mortality risk stratification in PPU patients treated at private regional hospitals with limited diagnostic resources.