Background: While evidence of the challenges of cancer caregiving has been growing, scant research addresses the experience of partners of young adults with cancer. These individuals and their relationships may be particularly vulnerable to stress, especially when managing the complexity of cancer care and survivorship with their partner. We sought to evaluate psychosocial concerns and mental health in the partners of young survivors of early stage breast cancer (BC). Methods: We invited partners of young women w/BC diagnosed at age ≤ 40 yrs enrolled in a prospective cohort study to participate in a one-time survey evaluating psychosocial concerns including quality of life, coping, social support, financial insecurity, partnership concerns, parenting concerns, anxiety and depression. Logistic regression was used to explore predictors of anxiety (score > 8 on Hospital Anxiety and Depression Scale (HADS)). Results: Most respondents (284/289) were male, with median age 43 yrs (range 27-65). The median time of survey completion was 62 months (range 16 -114) after their partner’s dx. Respondents were mostly white (93%), working full time (94%), and college educated (78%); 29% reported some financial stress, 74% were parenting children < 18 yrs, and 32% reported at least a fair amount of relationship concern. 42% (106/250) had anxiety (39/289 respondents (13%) had incomplete/missing HADS). In univariable analyses, lower education, working full time, parenting concerns, insufficient social support and maladaptive coping were associated (p < .05) with anxiety. In the multivariable model, only maladaptive coping remained significantly associated with anxiety (p < .01, OR = 2.32 (95% CI: 1.22, 4.39)). Conclusions: Partners of young BC survivors who used less constructive/more maladaptive coping strategies experience negative mental health outcomes after tx has ended. Caregivers’ anxiety may have implications for both their own and survivors’ health and QOL. Future interventions might focus on the development of constructive coping strategies to enhance adjustment and role effectiveness in dealing with the impact of cancer.