: The stress hyperglycemia ratio (SHR) has emerged as a promising biomarker for assessing stress-induced hyperglycemia (SH) but has not been evaluated in patients with acute pancreatitis (AP). This study investigates the role of the SHR in predicting adverse clinical outcomes in patients with AP. : Adult patients with AP who were admitted within 72 h of the onset of abdominal pain were screened in the database. Eligible patients with glycated hemoglobin (HbA1c) and blood glucose were analyzed. The SHR was calculated using admission blood glucose and HbA1c levels. Patients were categorized into four groups: SHR1 (≤1.03), SHR2 (1.04-1.25), SHR3 (1.26-1.46), and SHR4 (≥1.47). The primary outcome was persistent organ failure (POF). The secondary outcomes included acute peripancreatic fluid collection (APFC) and high-dependency unit/intensive care unit (HDU/ICU) admission. Restricted cubic spline (RCS) analysis was used to assess nonlinear associations and identify SHR threshold values. Univariable and multivariable logistic regression models were used to adjust for potential confounders and evaluate the relationship between the SHR and clinical outcomes. : A total of 486 patients with AP were included in this study, comprising 85 with POF and 401 without POF. SHR levels and severity were significantly correlated, with the highest quartile in the greatest proportion of severe acute pancreatitis (SAP). Higher SHR levels were significantly associated with an increased risk of POF, APFC, and HDU/ICU admission. RCS analysis revealed a nonlinear relationship between the SHR and APFC ( = 0.009). Based on the RCS and quartile analysis, SHR > 1.25 was identified as the threshold for increased risk. After adjusting for confounders, SHR > 1.25 remained independently associated with higher risks of POF (OR: 2.49, 95% CI: 1.39-4.46, = 0.002), APFC (OR: 2.85, 95% CI: 1.92-4.24, < 0.001), and ICU admission (OR: 1.74, 95% CI: 1.12-2.69, = 0.013). : The SHR is independently associated with adverse clinical outcomes in AP, including POF, APFC, and HDU/ICU admission. These findings suggest that the SHR may serve as a valuable biomarker for risk stratification and early intervention in AP management.