Fatigue is commonly reported by acute respiratory distress syndrome (ARDS) survivors, but empirical data are scarce.We evaluated fatigue prevalence and associated variables in a prospective study of ARDS survivors.This analysis is part of the ARDSNet Long-term Outcomes Study (ALTOS), conducted at 38 U.S. hospitals. Using age- and sex-adjusted, time-averaged random effects regression models, we evaluated associations between the validated Functional Assessment of Chronic Illness Therapy-Fatigue Scale (FACIT-F) with patient and critical illness variables, and with physical, cognitive and mental health status at 6- and 12-months post-ARDS.Among ARDS survivors, 501 of 711 (70%) and 436 of 659 (66%) reported clinically significant symptoms of fatigue at 6 and 12 months, respectively, with 41% and 28% reporting clinically important improvement and worsening, respectively (n=638). At 6 months, the prevalence of fatigue (70%) was greater than impaired physical functioning (50%), anxiety (42%) or depression (36%); 33% reported both impaired physical function and fatigue, and 27% reported co-existing anxiety, depression and fatigue. Fatigue was less severe in men and in those employed before ARDS. Critical illness variables (e.g., illness severity, length of stay) had little association with fatigue symptoms. Worse physical, cognitive and mental health symptoms were associated with greater fatigue at both 6- and 12-month follow-up.During the first year after ARDS, over two-thirds of survivors report clinically significant fatigue symptoms. Due to frequent co-occurrence, clinicians should evaluate and manage survivors' physical, cognitive and mental health status when fatigue is endorsed.