The total caries experience of 45 immunodeficient subjects was compared with that of controls matched for age and sex. Immunodeficient subjects exhibited significantly greater values in decayed, missing and filled teeth; decayed, missing and filled surfaces, and greater prevalence of caries of approximal and other smooth surfaces. No statistical differences were noted in caries experience of occlusal surfaces between the two groups. When groups of patients were compared on the basis of age (less than 13yr, 13yr and older) and immunodeficiency classification, caries experience was greater in immunodeficiency. Only minimal differences were observed in plaque and gingivitis scores. Patients deficient in oral immunoglobulins had greater caries experience than immunologically competent individuals. © 1981.