OBJECTIVES:The aim of this study was to compare the pattern of secretion and the expression of mucin glycoprotein-2 (MG2) and lactoferrin in individuals with or without periodontitis. MATERIAL AND METHODS: Five individuals with aggressive periodontitis (APG), 5 with generalized chronic periodontitis (CPG) and 5 without periodontitis (CG) were enrolled after informed consent. Non-stimulated and stimulated submandibular and sublingual saliva was collected and samples analyzed by Western blot probed with specific antibodies. RESULTS: Stimulated and non-stimulated salivary flow rates did not differ among groups. Western blot analysis revealed that stimulation led to: an increase in MG2 expression in all groups, and to lactoferrin expression in APG and CPG. In non-stimulated saliva, CG exhibited the highest expression of both glycoproteins. In stimulated saliva, CG exhibited the highest expression of MG2, whereas APG the highest of lactoferrin. CONCLUSIONS: The pattern of secretion of MG2 and lactoferrin in health and disease is complex. Although the present study analyzed samples from a limited number of participants, the reduced expression of MG2 and lactoferrin in APG and CPG under non-stimulated condition, the predominant circumstance of salivary secretion during the day, suggests that these salivary constituents may play a role in the etiopathogenesis of these diseases.