A great deal is at stake for children who are sexually abused; not only in the here-and-now, but also the possibility of long-term blight in their future relationships and mental health. This puts a heavy responsibility on the professionals who are required to investigate, and further assess for treatment or other interventions, cases where sexual maltreatment is confirmed or suspected. The multidimensional, multicomponent elements that make up an assessment (in particular, the ASPIRE process) are described here in terms of their practical and theoretical implications. The difficulties of finding reliable and valid methods (be they interviews or psychometric instruments) for this onerous task are discussed.