This chapters addresses the phenomenology, effects and implications for treatment of children and adolescents exposed to traumatic experiences of various types. The work of Lenore Terr first described the symptoms of children exposed to single traumatic events by directly interviewing children exposed to a single traumatic event. Later, she also described the phenomenon of repeated trauma (trauma type II) and the expectation and stress of further negative experiences. Her descriptions help understand the phenomenology and the need for psychological or multimodal interventions in those children. Dante Cicchetti conducted extensive research on a specific kind of trauma, namely, neglect, abuse (physical and sexual) and emotional abuse. This researcher and his colleagues took a developmental perspective to the traumatic or deprivation experiences. They described the identification with the abuser, dissociative experiences associated with them, as well as hyper arousal, excessive sensitivity to noises and the distorted perception of faces, seeing the world as dangerous and menacing. These descriptions allow he clinician understand the paradoxical behavior of many maltreated children, who become abusive or aggressive. Finally, intervention and treatment strategies are described, using a multimodal approach. Obviously there is a need for early identification and prevention strategies to assist children at risk of suffering maltreatment.