Purpose: Despite the theoretical and empirical significance of positive aspects of caregiving in caregiver well-being, relatively little is known regarding family-related predictors of caregiver positivity. This study examines whether patient-family communication (p-f communication) mediates the relation between family hardiness and caregiver positivity and whether the mediating effects of p-f communication are moderated by the levels of caregiver depression and anxiety. Design/Sample: This study used secondary data obtained from a large-scale cross-sectional national survey conducted in South Korea. Participants were 544 spousal cancer patient-caregiver dyads recruited from the National Cancer Center and nine government-designated regional cancer centers in South Korea. Methods: To test the hypotheses, a simple mediation model and two moderated mediation tests were conducted using the PROCESS macro for SPSS. Findings: Higher family hardiness was related to higher p-f positive communication and higher caregiver positivity. The effects of family hardiness were partially mediated by p-f communication, controlling for caregiver sex, education, health status, depression and anxiety, time spent caregiving, and patient depression and anxiety, cancer stage, and time since diagnosis. The mediating effects of p-f communication were not significantly moderated by caregiver depression and anxiety. Conclusions/Implications: Health care professionals could consider p-f communication as a reasonable target of intervention to increase caregiver positivity, even for caregivers with heightened depression and anxiety.