AimTo synthesise evidence related to risk factors of falls among younger mental health inpatients age ≤65 years old.BackgroundHospitalised patients with mental illness are at increased risk of falling. Specific risk factors for falls for younger inpatients are poorly understood.DesignSystematic review.MethodsMedline, CINAHL, APA PsycINFO, Scopus and Web of Science were searched for studies published in English till December 2022. The review followed the 2020 PRISMA checklist. Odds ratios and P values of significant risk fall factors and the frequency of factors related to circumstances of falls were extracted.ResultsNine studies were included and 95 risk factors, across seven categories were extracted. These categories included socio‐demographic, fall‐related factors, functional status, health and mental status, psychiatric diagnosis and assessment, medication, and staff related factors. Factors related to medication, health and mental status are most reported. Majority of the patients sustained minor or no injury from the fall and circumstances of fall vary across studies.ConclusionFactors strongly associated with risk of falls were dizziness, use of psychotropics and antihypertensive drugs. A meta‐analysis of risk factors was not possible due to different dependent variables studied, controlled confounding variables and control groups used.Relevance to clinical practiceFall prevention is relevant to all patients in mental health settings. Approaches to fall risk assessment and management need to be better tailored to younger mental health patients in the psychiatric setting.Patient and public contributionPatient or public contribution was not possible because of the study design.