Coenzyme Q10 (CoQ10) is an essential cofactor of the electron transport gene as well as an important antioxidant, which is particularly effective within mitochondria. A number of prior studies have shown that it can exert efficacy in treating patients with known mitochondrial disorders. We investigated the potential usefulness of coenzyme Q10 in animal models of Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS) and Huntington's disease (HD). It has been demonstrated that CoQ10 can protect against striatal lesions produced by the mitochondrial toxins malonate and 3-nitropropionic acid. These toxins have been utilized to model the striatal pathology, which occurs in HD. It also protects against 1-methyl-1,2,3,6-tetrahydropyridine (MPTP) toxicity in mice. CoQ10 significantly extended survival in a transgenic mouse model of ALS. CoQ10 can significantly extend survival, delay motor deficits and delay weight loss and attenuate the development of striatal atrophy in a transgenic mouse model of HD. In this mouse model, it showed additive efficacy when combined with the N-methyl-D-aspartate (NMDA) receptor antagonist, remacemide. CoQ10 is presently being studied as a potential treatment for early PD as well as in combination with remacemide as a potential treatment for HD.