Background: This study sought to elucidate the extent to which behaviour support plans for people with intellectual disability are inclusive of best practice criteria, with a comparison made prior to and following proclamation of the Disability Act (2006) in Victoria, Australia. Method: This study used a data collection instrument developed by the researchers incorporating best practice criteria as identified in the review of literature and Victorian legislative requirements. The instrument was used to assess a sample of behaviour support plans. Results: Best practice criteria are inadequately included in behaviour support plans with little difference between pre- and post-Act plans. Conclusion: The results of this study indicate that disability support staff are ill equipped to undertake the complex assessments, planning, and implementation associated with behaviour support strategies, despite the legislative framework that guides and directs this intervention. (Contains 2 tables.)