A survey was conducted on aggressive behaviour within a population of 2412 persons with intellectual disability in Queensland, Australia. Two hundred and sixty-one individuals were identified who engaged in at least one form of aggressive behaviour, yielding an overall prevalence of 11%. The relative prevalence of aggressive behaviour was higher among institutionalized persons (35%) when compared to those living in group homes (17%) or other community-based facilities (3%). The aggressive behaviour sample included a higher percentage of males (64%). Most were described as functioning in the severe/profound (54%) or moderate (31%) range of intellectual disability with one-third having no intelligible speech. Two-thirds of the sample received medication for their challenging behaviour, while only one-third had behavioural programmes. Eighty per cent engaged in three or more forms of aggression. Many also displayed self-injury (34%) or property destruction (30%). Surveys of aggressive behaviour may prove useful for coordinating services.