Background and goal: Sleep problems and challenging behavioural symptoms are frequently reported among nursing home residents with dementia. Coffee with caffeine is consumed frequently by these residents and can have a negative effect on sleep and behaviour in older persons with dementia. In this interventional study, the effect of caffeine reduction on sleep and challenging behavioural symptoms in nursing home residents with dementia was investigated. Methods: In 21 nursing home residents with dementia living in 1 dementia special care unit, caffeine was gradually eliminated in the afternoon and evening. During pre-intervention and post-intervention period the care workers daily scored sleep by a specially developed sleep questionnaire. Behavioural symptoms were scored in the afternoon and evening using four items of the NPI-NH: agitation/aggression, apathy, irritability and aberrant motor behaviour. Results: A significant improvement in sleep scores (Wilcoxon signed-rank test, p = 0.015) and apathy (Wilcoxon signed-rank test, p = 0.020) was found after eliminating caffeine intake in the afternoon and evening. No significant changes occurred in agitation/aggression, irritability and aberrant motor behaviour. Discussion: This pre-post pilot study found a significant positive effect of caffeine reduction on sleep and apathy and warrants further investigation in a larger controlled study.