Oxidative stress has been associated with the development of type II diabetes. Extracellular superoxide dismutase (ECSOD) is one of the enzymes responsible for the defense against oxidative damage in the extracellular space. The Ala40Thr polymorphism is located in the amino terminal domain. This study aimed to investigate the association of the ECSOD Ala40Thr polymorphism and the susceptibility to type II diabetes and/or its complications in the Lebanese population. For this purpose, a genotype analysis involving 60 type II diabetic patients and 40 control subjects was carried out using PCR followed by sequencing. There was not a significant association of Ala40Thr polymorphism with the susceptibility to type II diabetes (p=0.081). In addition, both BGL and HbA1C levels were significantly associated with Ala 40Thr polymorphism (p= 0.038-0.026). The development of diabetic complications was significantly associated with Ala40Thr polymorphism (p=0.03). In conclusion, the EC-SOD Ala 40Thr polymorphism was significantly associated with the increase level of BGL and HbA1c in type II diabetes in the Lebanese population and the development of complications in type II diabetic patients.