This study was designed to collect baseline data on dental status of 4-, 14- and 25- to 35-year-old Hong Kong residents who were mentally impaired and physically disabled. Participants were randomly selected from figures derived from a pilot survey, and dentally examined. The mean dmft/DMFT scores were 1.25, 2.27, and 5.23 (Missing component of 3.02), respectively. There was no correlation between caries experience and physical mobility, mental impairment, or sex in any age group. No visible plaque was found in 85.1% of 4 year olds (n = 309), 52.3% 14 year olds (n = 174), and 36.2% 25 to 35 year olds (n = 264). Visible plaque was recorded for 13.6% 4 year olds, 30.5% 14 year olds, and 47% 25 to 35 year olds. Abundant plaque was detected in 1.4% 4 year olds, 17.2% 14 year olds, and 15.8% 25 to 35 year olds. No calculus was observed in the 4 year olds, but 20.2% of 14 year olds had calculus as did 56.3% of the 25 to 35 year olds.