In 1990, 13 regionally based Behaviour Intervention Support Teams (BISTs) were established in Victoria to assist agencies providing support to persons with an intellectual disability who exhibited challenging behaviour. A primary function of the BISTs was to conduct intensive interventions for clients with severe challenging behaviours. The outcomes of the interventions conducted by eight of these teams were monitored over the period from 1991 to 1993. During this time, a total of 134 such interventions were completed by the teams. Many outcome measures were used for each intervention. These included direct observational measures of the challenging behaviours, measures of skill acquisition by the clients, and satisfaction with the results by caregivers. It was concluded that the interventions resulted in a high rate of success (approximately 75%). Additionally, it was concluded that the use of regionally based specialist teams was an effective way of treating severe challenging behaviours that had previously proven difficult to manage.