Coenzyme Q10 (CoQ10) is critical for the cell power supply in mitochondria. CoQ10 shuttles electrons from complexes I and II to complex III, and can be anti-oxdiative. Neurons require high energy for synaptic transmission and therefore the mitochondria dysfunction often leads to severe neuronal degeneration, as observed in many neurological disorders. CoQ10 supplementation has been widely used to treat aging, stroke, neuromuscular diseases, Alzheimer's disease, Parkinson's disease, progressive supranuclear palsy, autosomal recessive cerebellar ataxias, Huntington's disease and amyotrophic lateral sclerosis. Here we discuss a large number of preclinical and clinical trials for CoQ10 to elucidate the mechanisms underlying CoQ10 therapy. The rational applications as a therapeutic agent in neurological disorders are discussed.