This paper discusses the need to estimate the costs of an illness to properly allocate intervention resources for the various psychiatric disorders of childhood. Disorders that require the most community resources should be given the highest priority for early intervention programs. Factors to consider for estimating disorders which are most costly are discussed here: the incidence of the disorder, its severity, whether it is episodic or stable, and its impact on the individual family and the community. These factors contribute to the aggregate burden of suffering caused by a disorder.