Severe mental illnesses (SMIs) are disorders impacting one’s cognitive, behavioral, and/or emotional processes and can contribute to major functional and social impairments in both the lives of diagnosed individuals and their family members. This research study investigated the coping strategies used by family members of individuals diagnosed with SMIs and how these strategies affected the qualities of relationships among these family members. After using an online questionnaire distributed via social media and an undergraduate student subject pool to recruit participants, a final sample of 96 responses were analyzed. Regression analyses indicated denial and behavioral disengagement coping predicted lower levels of family cohesion and flexibility. Behavioral disengagement coping predicted fewer positive relationship qualities and more negative family relationship qualities. Positive reframing coping predicted more positive family relationship qualities, and greater levels of adaptability predicted more family cohesion and flexibility and fewer negative family relationship qualities. The results of this study give insight into previously overlooked familial relationships and provide direction for interventions to best meet the needs of family members of individuals diagnosed with SMIs.