Almost complete spontaneous recovery in visual function was observed in a male patient with Leber's hereditary optic neuropathy (LHON), in spite of the presence of several LHON-associated "major" and "minor" mutations of mitochondrial DNA. Our findings confirm that visual loss in LHON may be reversible, and challenge the hypothesis of a "synergistic" effect of multiple mtDNA mutations in the phenotypic expression of the disease.