Objective Depression and anxiety are common in dementia. There is a need to develop effective psychosocial interventions. This study sought to develop a group‐based adapted mindfulness programme for people with mild to moderate dementia in care homes and to determine its feasibility and potential benefits. Methods A manual for a 10‐session intervention was developed. Participants were randomly allocated to the intervention plus treatment as usual (n = 20) or treatment as usual (n = 11). Measures of mood, anxiety, quality of life, cognitive function, stress and mindfulness were administered at baseline and 1 week post‐intervention. Results There was a significant improvement in quality of life in the intervention group compared to controls (p = 0.05). There were no significant changes in other outcomes. Conclusions The intervention was feasible in terms of recruitment, retention, attrition and acceptability and was associated with significant positive changes in quality of life. A fully powered randomised controlled trial is required. Copyright © 2017 John Wiley & Sons, Ltd.