The objective of our study was to systematically review research evidence for relationships between self-efficacy beliefs and psychological as well as somatic outcomes of collective traumatic events. Twenty-seven studies enrolling adult and adolescent survivors of acute, escalating, and chronic collective trauma with a total of N = 8011 participants were reviewed. Cross-sectional studies suggest medium to large effects of self-efficacy on general distress, severity and frequency of PTSD (posttraumatic stress disorder) symptoms (weighted r values range from –.36 to –.77), whereas longitudinal studies indicate large effects on general distress and PTSD symptom severity (weighted r values range: –.55 to –.62). Self-efficacy was also related to better somatic health (self-reported symptoms, i.e., less pain, fatigue, or disability). Studies addressing the relationship between self-efficacy and substance abuse after collective trauma revealed a more complex picture. Some types of pretreatment self-efficacy (e.g., self-efficacy for coping with urges) or changes in efficacy beliefs may predict less substance use or relapses. Studies testing the mediating role of cognitive or social variables in the relationship among efficacy beliefs and health outcomes indicated rather direct, unmediated effects of beliefs about ability to deal with adversities on posttraumatic adaptation. Men may benefit more from stronger efficacy beliefs. In terms of reciprocity between self-efficacy and health, evidence from longitudinal studies suggested that self-efficacy determines health-related outcomes, but changes in diagnosis do not predict changes in self-efficacy. Although a lack of experimental studies limits the conclusions, the results indicated that self-efficacy is a powerful predictor of posttraumatic recovery among collective trauma survivors.