Patients with large body surface burns may be managed by primary excision of their full-thickness areas in an attempt to reduce the associated mortality rate. From past reports in the literature1,2 and from experience at this Unit3 it is evident that even with an experienced surgical team large amounts of blood are lost. Satisfactory replacement is generally obtained using such parameters as blood pressure, pulse, skin color, and hemoglobin determinations in association with visual estimation of the loss. However, these signs may be misleading in the severely burned patient during anesthesia. In this study we have evaluated the use of blood volume determinations for measurement of blood loss during excision procedures. Materials and Methods Blood volume measurements were made approximately one hour before and one hour after the excision procedure. Additional measurements were occasionally performed in the postoperative period when there was uncertainty and anxiety about the blood