Vascular dysfunction is a common consequence of diabetes mellitus. Stable propagation of gene expression from cell to cell generation during development of diseases (like diabetes) is regulated by epigenetic mechanisms. These are heritable patterns of gene expression that cannot solely be explained by changes in DNA sequence. Recent evidence shows that diabetes-induced epigenetic changes can affect gene expression in vascular endothelial cells and vascular smooth muscles cells. Such effects further influence inflammatory and insulin production pathways in these cells and thus ensure a long-term memory, whereby epigenetic changes are maintained even long after restoring normo-glycaemic conditions by appropriate therapeutic approaches. This review focuses on the epigenetic marks, which endure on the vascular chromatin under diabetic conditions.