Background: Poor oral health has been reported among various psychiatric populations. Little is known regarding the oral health among psychiatric patients in Asia. Aims: To examine the oral health status of a group of Chinese psychiatric inpatients in a long-term rehabilitation facility. Methods: A dental survey using the WHO standardised dental evaluation form was conducted in adult psychiatric patients in a rehabilitation programme. A qualified dentist examined all consenting patients. Results: Ninety-one patients (64.8% male; mean age: 44.7 9.9 years; mean length of illness: 20.3 11.5 years) were included in the study, the majority (80.2%) diagnosed with schizophrenia. Malocclusion was found in 79.1% of patients. The mean number of missing teeth was 9.5 8.9. Bleeding on probing, calculus, shallow and deep pockets were found in 7.1%, 71.8%, 72.9% and 28.2% of patients, respectively. Dental caries were found in 75.3% of dentate patients. The mean number of caries per patient was 5.5 6.1. Fifty-four per cent of patients needed dental extraction and 78.8% required conservative dental treatment. Older age and length of illness were significantly associated with poor dental health. Conclusions: Oral health status of chronic psychiatric patients seems to be considerably worse than that of the general population. Mental health professionals should pay more attention to preventive oral health habits of psychiatric patients.