Patients who are facing terminal illness frequently experience changes in health care settings which are necessitated by acute events during palliative care. This pilot study evaluates the reliability, criterion validity, and appropriateness of the San Diego Severity Index (SDSI) in a population of advanced cancer patients in different care settings. The SDSI includes diagnostic, acuity, and psychosocial assessments. Cancer patients were evaluated in an outpatient oncology clinic (SCRF), a hospice home care (HC) program, and an acute care hospital/hospice centre (ACC). Scores were lowest for SCRF (9.51 +/- 3.7), HC was intermediate (24.04 +/- 8.8), while patients at the ACC scored the highest (29.33 +/- 7.0). Patients admitted to the ACC were significantly more acute, as assessed by the SDSI, than those utilizing outpatient services. This instrument may be useful as an indicator of appropriate transitions between health care settings.