Background: People with an intellectual disability whose behaviours are perceived to be of serious harm to themselves or others are at risk of being subjected to restrictive interventions. Prevalence rates are difficult to determine, as most research is unable to draw on the results of population-level data. Method: The current study reports on the use of chemical and mechanical restraint and seclusion in the State of Victoria, Australia, over a 12-month period. Results: The majority of people included were subjected to chemical restraint. The use of restraint was found to be routine rather than a strategy of last resort. Consistent with findings in the UK and USA, those subjected to restrictive interventions were more likely to be young males with multiple disabilities, including autism. Conclusions: Systemic policy and procedural developments are needed to address current use of restrictive interventions, together with a longitudinal study to evaluate the effectiveness, of alternative, non-restrictive strategies.