Background: To prevent COVID-19 from spreading in long-term care facilities (LTCFs), the Dutch government took restrictive measures, including a visitor-ban in LTCFs. Objectives: This study examined the relationship between involvement of family caregivers (FCs) of people with dementia (PwD) living in LTCFs and FCs mental health during the visitor-ban, and whether this relationship was moderated by the frequency of alternative contact with PwD during the visitor-ban and FC resilience. Methods: This cross-sectional study collected data from 958 FCs. Findings: FCs who visited PwD more frequently before, were more worried during the visitor-ban than those with lower visiting frequency. FCs who visited the PwD daily before, but had minimal weekly contact during the visitor-ban, worried less. Resilient FCs who did social and task-related activities before, experienced less loneliness during the visitor-ban. Conclusions: It is advisable for healthcare professionals to reach out to these groups, to facilitate ongoing contact and help them overcome their loneliness.