Objective: This study aims to investigate the predictive value of non-traditional blood lipid indices for metabolism dysfunction-associated fatty liver disease (MAFLD) in non-overweight/obese patients with type 2 diabetes mellitus (T2DM).Methods: A retrospective observational study was conducted, including non-overweight/obese patients with T2DM who visited the Fourth Hospital of Hebei Medical University between August 2018 and August 2022. The low-density lipoprotein cholesterol (LDL-C)/high-density lipoprotein cholesterol (HDL-C) ratio, the triacylglycerol-glucose index (TyG) multiplied by body mass index (BMI), and TyG/HDL-C ratio were calculated.Results: The study involved 190 participants, of whom 34 were diagnosed with MAFLD (24 males and 10 females), while 156 did not have MAFLD (64 males and 92 females). Multivariable analysis revealed that aspartate transaminase (AST) (OR=1.216, 95% CI: 1.059-1.374, P=0.006), blood uric acid (BUA) (OR=1.017, 95% CI: 1.002-1.032, P=0.022), TyG*BMI (OR=1.231, 95% CI: 1.051- 1.442, P=0.010), and TyG/HDL-C (OR=3.162, 95% CI: 1.228-8.141, P=0.017) were independently associated with MAFLD. The TyG*BMI index exhibited an area under the ROC curve (AUC) of 0.812, with 91.2% sensitivity and 69.2% specificity for MAFLD. The TyG/HDL-C index had an AUC of 0.929, with 85.3% sensitivity and 88.5% specificity for MAFLD.Conclusion: The results indicate that TyG*BMI and TyG/HDL-C are independently associated with MAFLD in non-overweight /obese patients with T2DM.