Abstract In this relatively small sample of thirty-eight marmoset skulls, a relatively high incidence of several dental abnormalities has been observed; calculus, pigmentation, malocclusion in several forms, and mild to relatively extensive periodontal involvement. However, no evidence of dental caries was seen. In many of the skulls, there was observed to be an extensive rarefaction of the cancellous areas of the alveolar bone, often with large areas in which the trabeculae were absent. The frequently encountered comment that monkeys have little or no oral disorders obviously was not true for this sample of marmosets. Although little success was achieved in the maintenance of marmosets under laboratory conditions, the frequency of oral disease suggests the desirability of renewed efforts to develop experimental circumstances which would make their maintenance successful.