OBJECTIVES: Anxiety in older people is under-diagnosed and poorly treated despite significant impairments that arise from anxiety. Mindfulness-based cognitive therapy (MBCT) has been shown to be a promising treatment for anxiety. The aim of this study was to determine the effect of an MBCT program on anxiety symptoms in older people living in residential care. METHOD: Fifty-two participants (34 females) were randomly allocated into therapy and control groups using a 2 × 3 mixed design. The average age of participants was 83 years. RESULTS: The group effect showed significant improvements on all measures at the end of the seven-week program in the therapy group, while the control group did not show significant changes. CONCLUSION: This study represents one of the first studies of the effectiveness of an MBCT program on anxiety symptoms for older people using a randomized controlled trial. The study has implications for future research that include the effectiveness of MBCT for the treatment of anxiety symptoms in older people, the utility of group therapy programs in residential care and the benefits of using specialized instruments for older populations.