Quality end-of-life care in the adult critical care remains a high priority for numerous professional agencies and organizations due to advanced technologies that sustain or extent life, regardless of life quality. The purpose of this study was to describe how family members of patients in adult critical care attain awareness that their loved one is dying or near death in the adult critical care setting. Two research questions were addressed: 1) What is the human-environment health process of knowing that end-of-life is imminent by family members of patients in the adult critical care area?, and 2) What factors influence the human-environment health process of knowing that end-of-life is imminent by family members in the adult critical care area? A Glaserian grounded theory design was utilized to conduct this retrospective study. Both primary (interviews) and secondary (poem, nursing art, song, media and film) data sources supported the emerging theory. The Process of Death Imminence Awareness by Family Members of Patients in Adult Critical Care contained six phases: Patient's Near Death Awareness, Dying Right in Front of Me, Turning Points in the Patient's Condition, No Longer the Person I Once Knew, Doing Right by Them, and Time to Let Go. Influencing factors associated with this process were discussed as process facilitators and hindrances. Supportive nursing behaviors and actions as well as family member's emotional, behavioral, and physical reactions to having a critically ill family member were also discussed. This substantive theory will guide nursing education, practice, and research in the creation of nursing interventions, instrumentation, protocols, and policies and procedures aimed at providing cost effective quality end-of-life care in this specialized area of care.