The association among periodontal pathogenic microorganisms, periodontal disease and oral malodor has been strongly implicated but not proved. Although oral malodor is probably not caused by periodontal disease, there is ample evidence to suggest that periodontal disease increases the severity of oral malodor. Periodontitis worsens the severity of oral malodor by providing additional sites of VSC production (interdental and subgingival), an increased availability of sulfur-containing substrate (exfoliated epithelial cells and leukocytes) and an increased rate of methionine metabolism (precursor to methyl mercaptan). Periodontitis contributes to an increased tongue coating with higher VSC production. There is evidence to suggest that VSCs, i.e., oral malodor, may contribute to the progression and pathogenesis of periodontal disease via increased mucosal permeability. Treatment for oral malodor should be directed at eliminating or at least reducing the causative microorganisms and the associated substrates with diligent oral hygiene procedures. It is essential to diag nose and control any periodontal disease that may coexist and worsen the severity of oral malodor.