Rationale: Family members of critically-ill patients hospitalized in the intensive care unit (ICU) often become caregivers and they are at risk to develop adverse psychological outcomes. There is a need to understand the psychological impact of critical illness on family caregivers.; Objectives: The aim of this systematic review is to document the prevalence of depression, anxiety, and posttraumatic stress disorder (PTSD) in family caregivers of critically-ill patients and identify potential risk factors for psychological outcomes to inform clinical and future research recommendations.; Methods: A literature search for psychological outcomes for family caregivers of critically-ill patients was conducted. A total of 1,148 studies from PsycINFO, CINAHL, Web of Science, SCOPUS and Medline were identified.; Results: Forty studies met inclusion criteria and were included in the review. The prevalence of psychological outcomes in family caregivers ranged from 4% to 94% for depression, 2% to 80% for anxiety, and 3% to 62% for PTSD. Caregiver depression, anxiety, and PTSD decreased in most studies that assessed longitudinal outcomes. Common risk factors identified for adverse psychological outcomes included younger caregiver age, caregiver relationship to the patient, lower socioeconomic status, and female sex.; Conclusions: The prevalence of depression, anxiety, and PTSD varies greatly across studies of family caregivers of critically-ill patients. This finding highlights the need for more systematic investigations of psychological outcomes and the implementation of clinical interventions to prevent or reduce depression, anxiety, and PTSD in family caregivers of critically-ill patients.