Background: In the UK, people with intellectual disabilities who exhibit aggressive behaviour often receive community-based specialist health services from a community learning disability team (CLDT). Our aim was to estimate costs associated with this provision and to identify predictors of higher costs. Method: Costs were estimated for 60 adults with intellectual disabilities and aggressive behaviour who attended specialist psychiatric outpatient clinics in the West Midlands region of the UK, including contact time with members of the CLDT and use of psychotropic medication over a 12-month period. Results: Mean total cost of 12-month service provision was £418 (95% confidence interval [CI] £299-557). Mean total cost of 12-month psychotropic medication was £369 (95% CI £256-492). Amongst individual members of the CLDT, mean costs were highest for psychiatrists (£181) and relatively lower for community nurses (£70) and clinical psychologists (£30), and lowest for physiotherapists (£13). Male sex, presence of expressive verbal communication and presence of epilepsy were independently associated with 12-month medication and service use costs, accounting for 23% of the variance in cost. Conclusions: It seems that in terms of costs, there is an overreliance on medication and psychiatrists and a relatively lesser reliance on other CLDT members such as community nurses and clinical psychologists for the management of aggressive behaviour in adults with intellectual disabilities within community settings. Health commissioners may wish to explore this relative cost discrepancy further and try to redress the balance where appropriate.