A study was carried out of 121 elderly edentulous individuals living in institutionalised homes in the Lothian Region, Scotland to determine the prevalence of yeasts and associated oral disease. Clinical examinations found that 65(54%) of the individuals suffered from denture stomatitis, and yeasts were recovered from 51(78%) of these individuals. The main yeasts isolated were Torulopsis glabrata and Candida albicans. Culture of saliva samples produced a slightly higher recovery rate of yeasts compared with swabbing of the floor of mouth and palate. The number of cigarettes smoked per day had a significant positive effect on the presence of denture stomatitis. No difference in disease state was shown between secretors and non-secretors of blood group antigens in saliva. This study demonstrates a significant level of oral mucosal infection in an institutionalised elderly population.