Abstract Background A recent Dutch mono-centre randomised controlled trial has shown that occupational therapy improves daily functioning in dementia. The aim of this present study is to compare the effects of the Dutch community occupational therapy programme with a community occupational therapy consultation on daily functioning in older people with mild or moderate dementia and their primary caregivers in a German multi-centre context. Methods/Design A multi-centre single blind randomised controlled trial design is being used in seven health care centres (neurological, psychiatric and for older people) in urban regions. Patients are 1:1 randomised to treatment or control group. Assessors are blind to group assignment and perform measurements on both groups at baseline, directly after intervention at 6 weeks and at 16, 26 and 52 weeks follow-up. A sample of 140 community dwelling older people (aged >65 years) with mild or moderate dementia and their primary caregivers is planned. The experimental intervention consists of an evidence-based community occupational therapy programme including 10 sessions occupational therapy at home. The control intervention consists of one community occupational therapy consultation based on information material of the Alzheimer Society. Providers of both interventions are occupational therapists experienced in treatment of cognitively impaired older people and trained in both programmes. 'Community' indicates that occupational therapy intervention occurs in the person's own home. The primary outcome is patients' daily functioning assessed with the performance scale of the Interview for Deterioration in Daily Living Activities in Dementia and video tapes of daily activities rated by external raters blind to group assignment using the Perceive, Recall, Plan and Perform System of Task Analysis. Secondary outcomes are patients' and caregivers' quality of life, mood and satisfaction with treatment; the caregiver's sense of competence, caregiver's diary (medication, resource ...