Aims. To investigate the efficacy of applying a Montessori intervention to improve the eating ability and nutritional status of residents with dementia in long-term care facilities. Background. An early intervention for eating difficulties in patients with dementia can give them a better chance of maintaining independence and reduce the risk of malnutrition. Methods. An experimental crossover design was employed. Twenty-nine residents were chosen from two dementia special care units in metropolitan Taipei. To avoid contamination between participants in units using both Montessori and control interventions, two dementia special care units were randomly assigned into Montessori intervention (I1) and routine activities (I2) sequence groups. A two-period crossover design was used, with 15 residents assigned to Montessori intervention sequence I (I1, I2) and 14 residents assigned to Montessori intervention sequence II (I2, I1). On each intervention day, residents were given their assigned intervention. Montessori intervention was provided in 30-min sessions once every day, threedays per week, for eightweeks. There was a two-week washout period between each intervention. Results. There was a significant reduction in the Edinburgh Feeding Evaluation in Dementia score for the Montessori intervention period but not for the routine activities period, while the mean differences for the Eating Behavior Scale score, self-feeding frequency and self-feeding time were significantly higher than those of the routine activities period. Except for the Mini-Nutritional Assessment score post-test being significantly less than the pre-test for the routine activities period, no significant differences for any other variables were found for the routine activities period. Conclusion. This study confirms the efficacy of a Montessori intervention protocol on eating ability of residents with dementia. Adopting Montessori intervention protocols to maintain residents' self-feeding ability in clinical practice is recommended. Relevance to clinical practice. Montessori-based activities could provide caregivers with an evidence-based nursing strategy to deal with eating difficulties of people with dementia.