Neurodegenerative diseases (NDs) result from progressive deterioration of selectively susceptible neuron populations in different central nervous system (CNS) regions. NDs are classified in accordance with the primary clinical manifestations (e.g., parkinsonism, dementia, or motor neuron disease), the anatomic basis of neurodegeneration (e.g., frontotemporal degenerations, extrapyramidal disorders, or spinocerebellar degenerations), and fundamental molecular abnormalities (e.g., mutations, mitochondrial dysfunction, and its related molecular alterations). NDs include the Alzheimer disease and Parkinson disease, among others. There is a growing evidence that mitochondrial dysfunction and its related mutations in the form of oxidative/nitrosative stress and neurotoxic compounds play major roles in the pathogenesis of various NDs. Curcumin, a polyphenol and nontoxic compound, obtained from turmeric, has been shown to have a therapeutic beneficial effect in various disorders especially on the CNS cells. It has been shown that curcumin has considerable neuro- and mitochondria-protective properties against broad-spectrum neurotoxic compounds and diseases/injury-associating NDs. In this article, we have reviewed the various effects of curcumin on mitochondrial dysfunction in NDs.