Aims: This study aimed to investigate the psychometric properties of the Carers' Fall Concern Instrument (CFC‐I) for measuring carers' concern for older people (care recipients) at risk of falling. Background: Family carers are crucial in preventing older people from falling at home. Their concerns for older people at risk of falling have severe implications on carers' psychological well‐being and ability to prevent falls. However, there is no validated instrument measuring this concern. Methods: A cross‐sectional study was used to examine the validity and reliability of the CFC‐I. Carers looking after older people living at home completed the 17‐item CFC‐I and provided information about their care arrangements and the older people's fall history. Construct validity was tested using exploratory factor analysis and hypothesis testing. Internal consistency was determined by calculating Cronbach's alpha coefficient. Results: 143 carers completed the survey either by face‐to‐face or by online. After deleting one item with an item‐total correlation of below 0.3, the remaining 16‐item CFC‐I reported a Cronbach alpha of 0.93. Construct validity was supported by strong item‐total correlations (0.51–0.76), mean inter‐item correlations (0.47) and factor loadings (0.557–0.809). Factor analysis revealed three factors that include concerns about care recipients' health and function, living environment and carers' perception of fall and fall risk. The 16‐item CFC‐I can discriminate between carers of older people with and without recurrent (fallen 3/ more times) falls. Conclusion: The 16‐item CFC‐I is a valid and reliable scale for measuring carers' concern for the older people's risk of falling. Future analysis of test–retest and inter‐rater reliability of the instrument will further support its clinical use for carers. Implications for practice: The newly developed multi‐item CFC‐I can be used to quantify the carers' level of fall concern and inform targeted interventions for carers when caring for older people who are at risk of falling.