The effects of trauma have been the focus of study by several researchers. However, at present, there is no diagnostic criteria that includes all forms of clinical presentations of subjects who have been victims of prolonged trauma or that have started at developmentally vulnerable times in the victim's life. Unlike those individuals who are victims of a single traumatic event, individuals who suffer multiple traumas that occur at vulnerable times, are at risk of developing a complex trauma. The concept of complex trauma was introduced in the last decades and is characterized by a symptomatic pleomorphism: emotional instability, somatization, dissociation; changes in identity, pathological changes in interpersonal relationships and suicidal behavior. The present article describes the clinical features and tries to elucidate the main neurobiological variables involved in trauma. Finally, psychotherapeutic and pharmacological approaches are developed.