Over the past three decades, along with the development of the field of traumatology, it has become increasingly clear that the after-effects of trauma exposure extend beyond those experienced by survivors or perpetrators, to include their caregivers. The nomenclature in the field of indirect trauma includes three central terms to describe this experience: vicarious traumatization (VT), secondary traumatic stress (STS), and compassion fatigue (CF). The current encyclopedia entry comprises a comprehensive description of these constructs, with emphasis on the discipline of social work. As VT is based on the theory of constructivist self-development, this theory is addressed as well. Likewise reviewed are relevant theoretical frameworks for both STS and CF, diverse conceptualizations of CF, prevalence rates, risk factors, and microlevel, mezzolevel, and macrolevel recommendations for addressing secondary, vicarious, and CF trauma.