In response to periodontal pathogens neutrophils release oxidants, proteinases, and other destructive factors. The balance between these factors, the antioxidants, and endogenously synthesized antiproteinases determine the extent of periodontal damage. Malnutrition, particularly protein-energy malnutrition involving concomitant deficiencies of antioxidant nutrients, is characterized by impairment in production and cellular actions of the cytokines, diminished acute-phase protein response (APR) to infections, endocrinopathies, defective metabolism of drugs, and impaired response to stress. The APR plays a central role in promoting healing. Additionally, malnutrition elicits adverse alterations in the oral microbial ecology as well as in the volume and the antibacterial and physicochemical properties of saliva. Good dietary practices and optimal nutritional status are therefore important in mitigating the severity of inflammatory periodontal lesions but are likely of limited value if the stimuli from dental plaque are not removed.