Background: Dementia has a high burden for patients, informal caregivers and society. Given changes in care systems, more persons with dementia will live longer at home. However, living at home (with dementia) with a good quality of life is not easy to achieve. Dementia is often accompanied by neuropsychiatric symptoms like apathy, agitation, depression, and anxiety, which have a negative impact on quality of life. Whereas cognitive deterioration can hardly be influenced, it is possible to reduce neuropsychiatric symptoms. As autobiographical memories remain intact for a relatively long time in dementia, reminiscence interventions can promote feelings of pleasure and trust. The Online Life Story Book (OLSB) allows to digitally share memories (stories, pictures, video or audio fragments). The main objective is to study the effects of the OLSB on neuropsychiatric symptoms. The study has four secondary objectives: 1) to study the effectiveness of the intervention on the burden and quality of life of the primary informal caregiver 2) to provide a preliminary health-economic evaluation 3) to study the (time to) nursing home admittance as a longer term effect 4) to provide a process evaluation. Methods and design: A randomized controlled trial with individual randomization to one of two conditions is conducted: 1) intervention “Online Life Story Book”; 2) control condition (care as usual). Participants are persons with early dementia and their primary caregivers. In the intervention OLSB, a trained volunteer guides the participants through the process of putting together a timeline of their lives during 5 meetings within a period of 8-10 weeks. To assess the effects of the intervention on the primary outcome, neuropsychiatric symptoms, the Neuropsychiatric Inventory (NPI) will be assessed at three time points: before the intervention (baseline, T0), 3 months (T1) and 6 months (T2) post baseline.Discussion: When proven effective, the Online Life Story Book can be a valuable addition to the existing provision of care for persons with dementia and their informal caregivers. Trial registration: This study has been approved by the Twente Medical Ethics Committee under the file number p16-04 (Dutch Trial Register: NTR5939, date of registration: 14 March 2016).