Diabetes mellitus is a complex metabolic disease associated with peripheral and central complications. These complications include retinopathy, nephropathy and neuropathy. Several investigations have confirmed the role of oxidative stress in developmental diabetic mediated disorders, possibly via the formation of free radicals . Chronic antioxidant therapies may be useful in decreasing the risk of diabetic complications, from these antioxidants coenzyme Q10 which acts as an antioxidant, inhibiting lipid peroxidation and scavenging free radicals. This study aimed to investigate the brain oxidative stress induced by STZ in rats with consequent changes in brain neurotransmitters and examined the potential protective role of coenzyme Q10 (CoQ10) against the changes STZ induced. Our results cleared that coenzyme Q 10 seems to be a highly promising compound in protecting the diabetic rats against oxidative damage and preventing brain complications such as elevation of neurotransmitters.