Several scoring systems are used to predict prognosis in acute pancreatitis (AP), but their predictive success varies. This study compares the validity of the commonly used Bedside Index of Severity in AP (BISAP) score with the newly developed WL score and the Chinese Simple Scoring System (CSSS) score in predicting mortality and unfavorable prognostic outcomes in AP patients. This retrospective descriptive study included all AP patients presenting to the emergency department from June 2, 2019, to June 2, 2022. Patient demographics, vital signs, laboratory values, and imaging findings were recorded, and WL, CSSS, and BISAP scores were calculated. The effectiveness of these scores in predicting adverse outcomes and mortality was compared. Among 357 patients, 53.2% were male, with a median age of 62 years (interquartile range: 48-75). Area under the curve (AUC) values for 7-day outcomes were 0.956 for WL, 0.759 for CSSS, and 0.871 for BISAP; for 30-day outcomes, AUC values were 0.941 for WL, 0.823 for CSSS, and 0.901 for BISAP; and for poor prognostic outcomes, AUC values were 0.792 for WL, 0.769 for CSSS, and 0.731 for BISAP. In AP patients, WL, CSSS, and BISAP scores are effective predictors of unfavorable prognosis and mortality. WL score outperforms the CSSS and BISAP scores in predicting 7-day and 30-day mortality and poor prognosis. After WL, BISAP is the second-best system for predicting mortality. For predicting unfavorable prognoses, CSSS is the second-best system after WL. The simplicity of calculating the WL score based on four laboratory parameters makes it a preferable choice.