Family members (who are overwhelmingly women) providing caregiving for individuals with mental illness (MI) are known to experience significant burden. Little research, however, has addressed how such burden can affect caregivers’ personal time and perceived isolation. Using data from a survey of 1,505 family caregivers of adults with MI, authors examined the extent to which factors related to caregivers, care recipients, caregiving, and treatment are associated with caregivers’ perceived isolation and the mediating role of caregivers’ inadequate personal time. A series of multivariate logistic regression models and Sobel testing were performed. Half of caregivers perceived being isolated. Perceived isolation was positively associated with care recipients having a serious mental health problem, coresiding, effects of stigma, and caregivers having inadequate time for themselves. Perceived isolation was negatively associated with the ability to rely on others for help, caregivers being satisfied with the amount of community mental health services, and caregivers having received education on caregiving. Caregivers having inadequate time for themselves was most strongly related to perceived isolation. Female caregivers were more likely to experience isolation; however, this relationship was mediated through caregivers having less time for themselves than preferred. The article concludes with a discussion of the implications for social work practice.