Context: New-onset diabetes mellitus (DM) after the first attack of acute pancreatitis (AP) has not been fully elucidated. Objectives: The study aimed to explore the incidence and time-course of pancreatic endocrine insufficiency in patients with newonset prediabetes or DM after the first attack of AP. Data Sources: A comprehensive literature review was conducted by searching four major biomedical journal databases (PubMed, Embase, Cochrane Library, and Web of Science). Study Selection: We included all prospective clinical studies that investigated the change in the metabolization of glucose after hospital discharge following the first attack of AP. Data Extraction: After quality assessment, data were extracted according to a standard protocol. Because of between-study heterogeneity, data were analyzed by the random-effects method. Results: The inclusion criteria were met by 12 clinical studies, including 766 patients with the first attack of AP. Prediabetes and/or DM was observed in 51% (95% CI: 55% to 63%) of the patients after the first attack of AP. The pooled incidence of prediabetes and DM after AP was 23% (95% CI: 16% to 30%) and 18% (95% CI: 11% to 26%), respectively. The risk of new-onset prediabetes and DM significantly increased in 1-3 years (relative risk (RR): 4.00 (95% CI: 1.68-9.53)) and 3-5 years (RR: 2.12 (95% CI: 1.9-3.8)), respectively. Conclusions: New-onset prediabetes and/or DM after the first attack of AP developed in 51% of the patients after hospital discharge and the risk of DM increased more than two folds over three years.