The purpose of this study was to generate a grounded theory explaining the social and psychological processes used by spouses during the waiting period prior to heart transplantation. Theory discovery was accomplished using the grounded theory methodology. Life on Hold was identified as the basic social psychological process generated from the data that explains the responses of spouses during the waiting period prior to heart transplantation. Life on Hold is the process of "tabling" life's activities for an indefinite period of time in order to devote one's life to another person(s) or event. Spouses of heart transplant candidates set aside life's activities and focus all thoughts, actions, and energy on maintaining the life of the candidate until a donor heart is obtained. The process consists of two stages: Freeing Self and Making Life the Transplant. The theory provides a basis for the development of relevant interventions to assist family members to cope with the uncertainty and stress of the transplant experience.