Type 2 diabetes mellitus (T2DM) is a chronic metabolic disease of abnormal carbohydrate metabolism which is related with high morbidity and mortality rates caused by its complications. One of the major diabetes-related arterial phenotypes thought to be responsible for development of cardiovascular disease is endothelial dysfunction. Nitric oxide (NO) is a potent molecule derived of endothelium, which plays key role in control of vascular tone. In T2DM present endothelial dysfunction due to reduced NO bioavailability. Fish protein hydrolysates (FPH) have been showed to present antioxidant peptides (and high value of ACE inhibition activity. Therefore, the present study aimed to examine whether single dose of FPH ingestion would reversal macro- and microvascular endothelial dysfunction in T2DM.