The number of patients taking advantage of physician-assisted suicide, euthanasia or assisted suicide is increasing in those countries where these options are legal under defined conditions. The objective of this qualitative study was to explore the decision-making processes causing some chronically ill persons to continue their life or to end it. The preliminary theory answering the research question is based on 42 interviews with 30 adult patients, three relatives of patients who had died by assisted suicide, and two employees of a Swiss Assisted Suicide Organization. The conceptual model developed throughout the research process represents the theory about the decision-making processes of those physically chronically ill patients. It contains influencing factors and core categories which are central parts of constellations of living conditions that lead patients to end their life or to go on living. The findings indicate directions for health professionals, health care institutions and legislation in which to search for ways of dealing appropriately with the issue of assisted suicide for the chronically ill.