A comparison has been made between the serotypes of oral Candida albicans taken from patients with denture-induced stomatitis and from a group of age and sex-matched controls. C albicans isolates were obtained from the fitting surface of the denture, the palatal mucosa supporting the denture, and the buccal mucosa. Twenty-nine of the 30 patients samples in the group affected by denture-induced stomatitis had only C albicans serotype A on their palatal mucosa and denture surface, while mixtures of serotypes were obtained from the buccal mucosa of these patients. Only one patient had serotype B isolates from the palatal mucosa and denture surface. In contrast, the control group had mixture of A and B serotypes from both the denture surface and the palatal mucosa, as well as from the buccal sites sampled. It would appear from these results that denture-induced stomatitis is associated with the proliferation of a single C albicans serotype, usually serotype A.