Abstract: Objective To assess the relationship between plasma homocysteine with chronic complications in type 2 diabetes mellitus.Method Plasma homocysteine levels, blood glucose, and HbA1c were measured in 60 diabetic patients (including 30 with and 30 without complications) and 31 normal subjects. The difference in the occurrence of chronic complications between patients with and without hyperhomocysteinemia was investigated.Results Plasma homocysteine level was significantly higher in type 2 diabetic patients with chronic complication than in normal control subjects (P<0.01), and patients with chronic complications had higher homocysteine levels than those without chronic complications (P<0.01).Conclusion Hyperhomocysteinemia is related to chronic complication in 2 diabetes mellitus, possibly due to the injury to the vascular endothelium by homocysteine.