The aim of this study was to examine physicians' and nurses' preferences regarding the use of life-sustaining treatments (LST) for severely ill elderly patients, and the patient- and social-centered factors that influence them. Physicians and nurses working in Israeli general hospitals completed structured questionnaires referring to their preferences for using LST in three severe health conditions (metastatic cancer, mental illness and being bedridden/incontinent). The participants were also asked about factors influencing these preferences, including patients' wishes, quality of life, religiosity and the current law. Both physicians and nurses indicated that they would use less LST for patients with metastatic cancer than with those suffering from the other two health conditions. Our findings indicate that the attitudes of professionals involved in these processes are influenced not only by the patient's condition but also by their professional orientations and personal values. Open communication among professionals for clarifying the various beliefs, as well as the antecedents of these beliefs, is important for the benefit of professional teams, patients and families.