Coenzyme Q10 (CoQ10) is a component of electron transport chain and acts as an antioxidant. It is also used for preventing neurodegeneration against mitochondrial deficiency and oxidative stress. Therefore, CoQ10 has received increasing attention as therapeutic and preventive intervention for neurodegenerative diseases. This review article focuses mainly on the structure of CoQ10, the function of CoQ10 and the relationship between mitochondrial impairment, oxidative stress and neurodegenerative diseases. In addition, the effects of CoQ10 on Alzheimer's disease, Parkinson's disease, and Huntington's disease are also discussed. Finally, future perspectives regarding development of successful treatment for neurodegenerative diseases are proposed.