Background: Hospitalization in the Intensive Care Unit (ICU) brings about psychological and physical symptoms in patients' family members. Family Intensive Care Unit Syndrome (FICUS) is a term used to explain the psychological symptoms of the family of a patient in response to the patient's admission to the ICU. The purpose of this study was to define FICUS along with its symptoms and predictors. Materials and Methods: The Web of Science, PubMed, Scopus, Google Scholar, and SID databases were searched for literature published in 2005-2018 with the keywords "FICUS," "intensive care unit," "family," "caregivers," "anxiety," "depression," and "post-traumatic stress disorder" in their title and abstract. The strategy for conducting an integrative review provided by Whittemore and Knafl (2005) was used in this study. Results: Twenty articles were included in the final data analysis. Following the patient's admission to the ICU, family members experience multiple psychological symptoms such as FICUS. The most commonly reported symptoms were anxiety, depression, post-traumatic stress disorder (PTSD), complicated grief, sleep disorder, stress, and fatigue. The low education level, having a critically ill spouse, adequate support, financial stability, preference for decision making, understanding of the disease process, anxiety, depression, or previous acute stress were predictors of FICUS. Conclusions: On the basis of the results, families also experience physical symptoms, so the FICUS is not limited to the occurrence of psychological symptoms. This study found that there is no universal definition for the term "FICUS" in the research literature. Thus, further research is needed to explore FICUS in the health field.