Stomatologic fungal infections display different etiologies, pathogenesis, and clinical presentations. The incidence of rare mycoses of oral cavity is very low. These infections can involve both immunocompromised and immmunocompetent patients with common predisposing factors, such as diabetes or suffering from diseases causing immune system impairment. Oral mycoses can cause acute, chronic, and mucocutaneous lesions. Candidiasis is the most common mouth mycosis. Although occasionally primary mouth pathogens, Cryptococcus spp. or filamentous fungi (Aspergillus spp. and zygomycetes) can cause oral mycoses, with the oral localization more commonly secondary to a more serious systemic infection. The diagnosis of oral mycoses is based on clinical examination; for yeasts, culture is necessary to identify the etiologic agents; for filamentous fungi, in particular for zygomycetes and dimorphic, a definitive diagnosis can be made by histologic examination and pertinent stains with or without isolation of the fungus from the same site.