Background: Persons with intellectual disability often evince challenging behaviours. Efforts have been underway for some time to develop prosocial or positive skill acquisition treatments to address challenging behaviours. However, physical/mechanical and chemical restraint is still commonly used in many clinical and community settings. Such interventions may be planned or unplanned and in some cases implemented by staff/parents with little training. Method: Physical/mechanical and chemical restraint and the factors that may result in the use and maintenance of restraint are reviewed. Results: The type, rate and intensity of challenging behaviours, and the age of the affected individual and residential placement appear to be among the major factors that put these persons at risk for restraint. Conclusions: Restraint is still a commonly used intervention employed with people with challenging behaviours. Physical and chemical restraint should be used as a last resort, part of a planned programme, and implemented by trained people.