Hypertriglycaeridemia has been positively associated with the risk of acute pancreatitis, but whether increased triglyceride (TG) levels are related to the severity of pancreatitis remains unclear. The aim of this study was to assess the relationship between hyperlipidaemia and disease severity of hypertriglycaeridemic pancreatitis. From 2016 to 2018, patients with hypertriglyceridaemic pancreatitis presented within 24hours from symptom onset were retrospectively enrolled. The severity was classified by the Atlanta classification 2012. The demographic and clinical characteristics of patients were compared with respect to severity stratification and different TG categories, respectively. The relationships of admission TG levels and disease severity were assessed with Spearman's rank correlation test and Linear-by-Linear Association test. Among 256 patients included, 125 (48.8%) were diagnosed with mild (MAP), 76 (29.7%) with moderate (MSAP) and 55 (21.5%) with severe acute pancreatitis (SAP). The mean TGs (standard derivation) on admission in patients with MAP, MSAP and SAP were 21.6 (15.2) mmol/L (1913 [1346] mg/dL), 34.6 (22.6) mmol/L (3065 [2002] mg/dL) and 41.5 (32.5) mmol/L (3676 [2879] mg/dL), respectively (P<.001). Patients were then categorised based on their TG levels. TG categories had a strong positive correlation with the disease severity (Rho=0.34, P<.001). Positive trend for the association across increasing TG categories and SAP was observed (P<.001). Elevated serum TG levels at the time of admission seem to correlate positively with the severity of hypertriglyceridaemia-induced acute pancreatitis.