In this study, we aimed to evaluate the effect of monocyte/high-density lipoprotein (MHR), which is associated with systemic inflammation: on prolonged hospitalization in patients with mild acute pancreatitis. Patients hospitalized for acute edematous pancreatitis between 01.01.2021 and 31.12.2021 were retrospectively screened. Arrival Ranson scores of the patients were calculated. Those with a Ranson score <3 were considered as mild acute pancreatitis and were included in the study. Patients with mild acute pancreatitis were divided into 2 groups with a hospital stay of <8 days and ≥8 days. Monocyte/HDL, biochemical and metabolic parameters were compared between the groups. The study was conducted with a total of 39 patients, 23 male (59%) and 16 female (41%). While 28 (71.8%) of the patients were discharged within <8 days, 11 (28.2%) were hospitalized for ≥8 days. Group ≥8 days was considered as prolonged hospitalization. It was determined that the monocyte/HDL ratio was significantly higher in the group with prolonged hospitalization between the groups. In univariate analyzes, it was determined that the presence of Diabetes Mellitus and MHR increased the risk of prolonged hospitalization by 5.25 times and 1.085 times, respectively. In the multivariate analysis of these two parameters, MHR was found to be an independent risk factor for prolonged hospitalization. It was concluded that monocyte/HDL can be used as a simple and reliable parameter to predict the duration of hospitalization in patients with mild acute pancreatitis.