Background: Insulin resistance is a well-known derangement after an attack of pancreatitis but the role of dietary fat intake and intra-pancreatic fat deposition (IPFD) in it is unknown. We aimed to investigate the relationship of dietary fat intake with markers of insulin resistance in individuals after acute pancreatitis, taking into account IPFD. Methods: This was a cross-sectional study. The EPIC-Norfolk food frequency questionnaire was used to determine the habitual intake of saturated, monounsaturated, polyunsaturated fatty acids. The studied markers of insulin resistance were fasting insulin, HOMA-IR, and METS-IR. 3 T magnetic resonance imaging was used to quantify IPFD. Linear regression analysis, with adjustment for possible confounders, was performed. Results: A total of 111 individuals after acute pancreatitis (33 low IPFD, 40 moderate IPFD, and 38 high IPFD) were included. In the high IPFD group, intake of monounsaturated fatty acids was inversely associated with both fasting insulin, and HOMA-IR, and METS-IR in the unadjusted (f3 = -65.405, p < 0.001; f3 = -15.762, p < 0.001; f3 = -0.760, p = 0.041, respectively) and fully adjusted models (f3 = -155.620, p < 0.001; f3 = -34.656, p < 0.001, f3 = -2.008, p = 0.018, respectively). Intake of polyunsaturated or saturated fatty acids did not have a consistently significant pattern of associations with the three markers of insulin resistance. None of the above associations was significant in the low IPFD and moderate IPFD groups. Conclusions: Habitual dietary fat intake is associated with insulin resistance only in individuals after an attack of pancreatitis who have high IPFD. These indviduals may benefit from a calorically balanced diet that is rich in monounsaturated fatty acids. (c) 2021 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.