This study aims to evaluate impaired insulin tolerance among Vietnamese diabetes with or without dyslipidemia. Diabetes mellitus (DM) remains the serious global health and social burden that has increased over the past few decades. It progresses silently to vascular injury and disability of injured vascular-perfused tissues/organs. Insulin intolerance and dyslipidemia exacerbate and accelerate the implications of DM. Thus, early detection and more evidence of early insulin intolerance and dyslipidemia is needed for proactive management. This cross-sectional descriptive study recruited 100 healthy control (HC) and 297 DM patients in Military Hospital 103 from 2021 to 2023. Patients with DM were subgrouped into lipid metabolism disorder (LMD, n = 98) and non-LMD (NLMD, n = 99). The biochemists' serum levels were measured automatically and the accuracy of the test result was strictly controlled. Insulin tolerance indices (HOMA2-IR, HOMA2-%S and HOMA2-%B) were compared between HC, DM with or without dyslipidemia as well as correlated with lipid ingredients (total Cholesterol, triglyceride, LDL-C and HDL-C). Among DM patients, HOMA2-IR was significantly high and HOMA2-%S and HOMA2-%B were significantly low. HOMA2-IR was higher and HOMA2-%S and HOMA2-%B were lower in DM with LMD than in DM without LMD. In addition, HOMA2-IR was positively correlated with serum cholesterol, triglyceride and LDL-C concentration, and negatively correlated to HDL-C concentration. In contrast, HOMA2-%S and HOMA2-%B was negatively correlated with serum cholesterol, triglyceride and LDL-C, and positively correlated with HDL-C. Impaired insulin intolerance occurred in early stage of DM, and more serious among DM with LMD, compared to DM with NLMD.