Patients with IgA deficiency and agammaglobulinemia were pair-matched to immunocompetent subjects by age and Plaque Index. Clinical examinations performed initially and after 2 years included the Plaque Index, Gingival Index, Periodontal Disease Index, caries experience (DMF-T) and full mouth radiographic surveys. Therapy during the 2-year period included oral hygiene instructions, prophylaxis and indicated restorative treatment. Immunodeficient patients manifested consistently lower levels of gingival inflammation than matched immunocompetent patients at both examination periods. Caries experience of immunodeficient patients was also less during the study interval, and five of these patients demonstrated DMF-T scores of zero. No developmental abnormalities, acute gingival or mucosal lesions, or attachment loss associated with periodontitis was observed in either group.