Objective To describe the level and influencing factors of fear of missing out in young and middle-aged patients with liver failure, and to provide a reference for developing intervention plans.Method A total of 247 young and middle-aged patients with li-ver failure were surveyed using a general information questionnaire, the Family APGAR Index, the Resourcefulness Scale, and the Fear of Missing Out Scale.Result The participants scored (25.33±1.86) points for fear of missing out.Multiple linear regression showed that age, education level, resourcefulness level, and family functioning were the influencing factors of fear of missing out in young and middle-aged patients with liver failure (all P＜0.05), which could explain 40.5% of the total variance.Conclusion The fear of missing out in young and middle-aged patients with liver failure is at a moderate level, and is affected by several factors.Targeted intervention measures should be developed in an individualized manner to improve patients′ family functioning and resourcefulness level, thus to reduce their fear of missing out.