This paper reviews the literature on child and adolescent sexual abuse. It is considered as a type of child maltreatment with potential negative psychological consequences. Child sexual abuse (CSA) definitions and characteristics are considered together with prevalence and distribution data showing the magnitude of this worldwide problem. There is a brief description of child and adolescent sexual abuse and its short and long-term psychological consequences, and also an analysis is made of physical problems as a result of CSA. The main issues of CSA psychological evaluation are discussed, in particular the forensic and clinical aspects of the assessment process comparing strategies and techniques in both areas. Finally, some of the current clinical psychological treatments for CSA are reviewed based on objectives and goals, and their effectiveness. Prevention program models are analyzed, specifically school based interventions. In spite of advances in research knowledge about CSA, there are still many methodological difficulties and challenges in the field. Nevertheless, some of these challenges are well known and ongoing research is addressing them.