Background: The ecological perspective recognizes the critical role that is played by rehabilitation personnel in helping people with intellectual disability (ID) to exercise self-determination, particularly in residential settings. In Hong Kong, the authors developed the first staff training programme of its kind to strengthen the competence of personnel in this area. The purpose of this study was to examine the effectiveness of staff training in enhancing residential staff's attitudes, knowledge and facilitation skills in assisting residents with ID to exercise self-determination. Methods: A pretest-posttest comparison group design was adopted. Thirty-two participants in an experimental group attended a six-session staff training programme. A 34-item self-constructed scale was designed and used for measuring the effectiveness of the staff training. Results: The results showed that the experimental group achieved statistically significant positive changes in all domains, whereas no significant changes were found in the comparison group. Conclusions: The findings provided initial evidence of the effectiveness of staff training that uses an interactional attitude-knowledge-skills model for Chinese rehabilitation personnel. The factors that contributed to its effectiveness were discussed and recommendations for future research were made.