Assessment as a term is used in three ways in relation to child sexual abuse: (1) assessment of whether child sexual abuse has occurred; (2) assessment of the degree and extent of subsequent risk to the child; and (3) assessment of requirements for and responses to intervention and treatment. The author focuses on the first two ways assessment is used in his examination of child sexual abuse. He notes the principal aim of the assessment process is to determine whether sexual abuse has occurred and then develop a clear account of it. The author describes a planned approach to investigation that involves a partnership with parents and children and talking with children. He also outlines stages of the investigative process--referral, immediate response, consultation and planning, information gathering and processing, investigative interview, child protection planning, and taking action to protect the child. Guidelines are offered on how to conduct assessment interviews to obtain information on the alleged abuser and the family. 26 references and 1 figure