Seven brands of intravenous fluid administration sets were studied to determine: (1)which set(s) maintained the most consistent flow rates; (2) if the type of fluid container (open, vented or closed, nonvented) affected the flow rates of administration sets; and (3) which set(s) closely approximated the theoretical amounts of fluid to be delivered in one hour at flow rates of 60,100 and 125 ml/hour. Six samples of each brand of administration set were tested in a laboratory setting which approximatedclinical conditions. The type of fluid container had little effect on the performance of the administration sets. The ARDL set was the most accurate in terms of the average volume of fluid delivered in 24 hours. The Burron set required fewer adjustments in 24 hours to maintain a constant flow rate. The U.S. Surgical set recordedthe smallest percent change in flow rate at the end of the first hour. The U.S. Surgical set is rated superior in overall performance. Based on the results of the study,the authors make recommendations to health care personnel, the pharmaceutical industry and the U.S. Pharmacopeial Convention.