To determine the effects of Haemaccel upon liver, kidney, serum electrolytos and hemostatic functions, 500 ml. of 3.5% Haemaccel solution was administered intravenously to 20 patients during elective surgery. In all cases estimated blood loss was less than 600 ml. without replacement. RBC, WBC, hemoglobin; hematocrit, ESR, platelet, bleeding time, coagulation time and prothrombin time were determined immediately before, and again 30 minutes and 5 hours after infusion; and total protein, albumin, total bilirubin, direct bilirubin, SGOT, SGPT, alkaline phosphatase, BUN, sodium and potassium were ehecked immediately before, and again 5 hours and 24 hours after the end of infusion. The results are as follows: 1) No anaphylactic shock or bleeding tendency characteristic of colloids was encountered. 2) No functional disturbances of liver or kidney directly attributable to Haemaccel were identified. 3) No pathological changes were noted in general laboratpry parameters except for elevated ESR, probably due to decreased blood viscosity, dilution of blood and to pseudoagglutination of red cells.