Recent studies have detected mutations in the EDA gene, previously identified as causing X-linked hypohidrotic ectodermal dysplasia (XLHED), in two families with X-linked non-syndromic hypodontia. Notably, all affected males in both families exhibited isolated oligodontia, while almost all female carriers showed a milder or normal phenotype. We hypothesized that the EDA gene could be responsible for sporadic non-syndromic oligodontia in affected males. In this study, we examined 15 unrelated males with non-syndromic oligodontia. Three novel EDA mutations (p.Ala259Glu, p. Arg289Cys, and p.Arg334His) were identified in four individuals (27%). A genetic defect in the EDA gene could result in non-syndromic oligodontia in affected males.