BACKGROUND: Coping with behavioral changes is a daily challenge for family caregivers in all phases of dementia, and assistance is needed for it. An online self-management support intervention was therefore developed and conducted involving the following elements: (1) email contact with a specialized dementia nurse, (2) online videos, and (3) e-bulletins containing information about behavior changes and how to manage them. OBJECTIVE: The aim of this study was to understand (1) family caregivers' actual use of various elements of the online self-management support, (2) family caregivers' evaluation and satisfaction with the various elements, and (3) nurses' usage and evaluations of the online support through the tailored email contacts. METHODS: A mixed methods design was used in this process evaluation, combining quantitative and qualitative methods including analyses of dementia nurses' registration forms, the number of clicks on online videos and e-bulletins, evaluation questions answered by family caregivers in a survey questionnaire, semistructured interviews with family caregivers and nurses, and analysis of the content of the email contacts. RESULTS: The actual use of various elements of the online self-management support by family caregivers varied: 78% (21/27) of family caregivers had an email contact with the specialist nurse, 80% (43/54) of family caregivers clicked on an online video, and 37% (30/81) clicked on an e-bulletin. Family caregivers showed positive evaluations and satisfaction. The tailor-made approach in the personal email contacts in particular was valued by the family caregivers. Nurses' evaluations about providing self-management support online were mixed as it was a relatively new task for them. CONCLUSIONS: An important insight is that not all participants made optimum use of the various elements of the intervention. Nurses also said that the email contacts were more often used to express feelings about coping with behavioral changes. More research is needed to investigate the reasons why people accept, adopt, and adhere to online interventions to reduce cases where they are not used and to back them up appropriately with tailored (online) information and advice for their personal situations.