Aim: Diabetes is a systemic disease with increased oxidative damage, lipid oxidation and decreased prevention of LDL oxidation. Some of the preventive effects of HDL is thought to be mediated by paraoxanase. Paraoxonase activity is reduced in diabetes. Aminoguanidine, inhibits the formation of advanced glycation endproducts by reacting with intermediate products of glycation. We aimed to investigate the effects of the inhibition of advanced glycation by aminoguanidine on paraoxonase activity in a diabetes model.