Septicemia is a possible complication of the administration of intravenous infusions. The infection may be derived from the skin or from contaminated infusion fluid. The risk to the patient from contaminated infusion fluid depends on the number of organisms present and, therefore, on the nutrient properties of the fluid. A number of commonly used infusion fluids were tested for their growth-promoting abilities for a variety of bacteria. Some fluids did not support the growth or survival of any of the test organisms, whereas other fluids offered selective advantages to different organisms and permitted growth at different rates and even at a pH as low as 3.5.