Background: Family caregivers of patients in the intensive care unit (ICU) experience impairments in the quality of life. Previous studies report that psychological quality of life improves over time, but there has been limited longitudinal research, and measurement points have differed. Factors such as age, gender, and posttraumatic stress symptoms have been found to be associated with the quality of life, but level of hope and its associations with the quality of life have not been investigated.; Objectives: The objective of this study was (1) to evaluate changes in the quality of life in family caregivers during the first year after a patient's admission to the ICU and (2) to identify associations between patients' and family caregivers' background characteristics, posttraumatic stress symptoms, hope, and quality of life.; Methods: A longitudinal study design with five measurement points was used. Family caregivers completed study questionnaires at enrolment into the study and at 1, 3, 6, and 12 months after the patient's admission to the ICU. The quality of life was measured with the 12-Item Short Form Health Survey.; Results: Family caregivers (N = 211) reported improved psychological quality of life during the first year after the patient's admission to the ICU, but it was still lower than the psychological quality of life reported in norm-based data. Being on sick leave, consulting healthcare professionals (e.g., general practitioner), and increased level of posttraumatic stress symptoms were significantly associated with psychological quality of life, whereas hope was not. Reported physical quality of life was comparable to norm-based data.; Conclusion: Family caregivers of patients in the ICU reported impairments in quality of life during the first year after the patient's admission to the ICU. Being on sick leave, consulting healthcare professionals, and reduced posttraumatic stress symptoms may improve mental quality of life.