 The human body is exposed to agents that produce free radicals which cause oxidation of cellular machinery. To counteract these effects, the body has endogenous and exogenous antioxidant systems. An imbalance between reactive species and antioxidants leads to oxidative stress, which can result in pathological conditions such as diabetes. Biomarkers of oxidative stress in diabetes include lipids, proteins, DNA damage, glutathione, catalase, and superoxide dismutase. Oxidative stress-induced complications of diabetes may include stroke, neuropathy, retinopathy, and nephropathy. This article was authored by Asmet Ula, Abad Khan, and Ismail Khan.