The purpose of this study was to conduct a comparative analysis of hospital costs incurred by patients undergoing Cardiovascular Surgery (CVS) and patients undergoing other medical procedures who received Continuous Renal Replacement Therapy (CRRT) in a teaching hospital. A total of 117 patients were identified through review of medical charts for the period of January 1999 to August 2002. Twenty one percent of them were identified having CVS. Eighty-eight percent of the CVS patients admitted to the ICU for CRRT died compared to 67% for non-CVS patients (p=0.047). Average actual costs of hospitalization were $47,225 for CVS patients and $51,724 for non-CVS patients. The mean length of stay (LOS) was 12.8 days for the CVS patients and 18.1 days for other patients (p=0.03). Mean LOS for patients who survived was 23.1 days whereas the average LOS for patients who died was 14.5 days (p=0.06). The differences found between patients who had CVS with CRRT as compared to non-CVS patients with CRRT in terms of mortality and length of stay raise ethical as well cost effectiveness questions of the procedure.