HIV infection reduces oral defensive mechanisms and may affect mucosal integrity. Differences in salivary protein concentrations and periodontopathogenic bacteria were studied in 56 HIV-infected patients with respect to their disease phase. Thirty-three patients were followed up for 2 years. Fifty-three healthy subjects of corresponding age and sex were studied as controls. At baseline, salivary albumin, total protein, IgA, and IgM levels were significantly higher (P<0.05-0.0001) in all phases of HIV infection, except the asymptomatic (ASX) phase, when compared with the control group. IgG levels were significantly increased in all phases except the ASX phase (P<0.05). After 2 years, salivary total protein, IgG, and IgM levels were still higher (P<0.05-0.005) in all HIV phases when compared with the control group (P<0.05-0.005). The albumin level was significantly higher in the ASX phase (P<0.005) and in the AIDS-related complex phase (ARC) (P<0.05), while the increase in IgA level was significant only in the ARC phase (P<0.005). Periodontopathogenic bacteria analyzed by PCR were detected both in the patients and the non-infected, but a statistically significant difference in the carriage percentage between the follow-up lymphadenopathy syndrome phase (LAS) and the control group was found only in Porphyromonas gingivalis (P<0.05) and Bacteroides forsythus (P< 0.0001). Thus, HIV infection appeared to cause a significant increase in the studied salivary proteins, suggesting leakage of serum components into the mouth.