The purpose of this study was to describe the state of the dentition of middle-aged and elderly Chinese in Hong Kong in terms of teeth present, tooth spaces, and prosthetic treatment received. In an oral health survey conducted in 1991 in Hong Kong, a sample of 372 35-44-yr-olds and 537 noninstitutionalized 65-74-yr-olds was interviewed and clinically examined. In all dentate subjects, each tooth was scored for the presence/absence of that tooth, a tooth space of 5.5 mm which had not been treated, or the presence of a denture or pontic replacing that tooth. Each denture was assessed according to a set of criteria. None of the 35-44-yr-olds were edentulous and the mean number of teeth present was 27.5. About 40% of the third molars and about 35% of the mandibular first molars were missing. For only 1% of the missing teeth had space closure resulted in missing teeth not being recorded as tooth spaces or treated tooth spaces. Overall, 72% of the 35-44-yr-olds had no prosthesis, 17% had a bridge or bridges, 12% had a denture or dentures, and 1% had both. Of the 65-74-yr-olds, 12% were edentulous, and the dentate subjects had a mean number of 17 teeth present. About 70% of the molars were missing. Overall, only 29% of the elderly had no prosthesis, 52% had a denture or dentures, 33% had a bridge or bridges, and 13% had both. Only 35% and 28%, respectively, of the middle-aged and elderly denture wearers had no complaint about their dentures. There were more assessed problems in the dentures of the elderly than in those of the younger adults, over one-third of the partial dentures and half of the mandibular complete dentures being unstable and unretentive.