A new disposable clamp for monitoring intravenous infusion rates has been evaluated in a series of 20 patients. This clamp takes into account the complex physical characteristics of plastic tubing under stress and provides less than a 10% change in infusion rate over a one-hour period. In contrast the most commonly used commercial roller infusion clamp permits an average decrease in flow rate of greater than 50% in one hour. The new clamp has a V-shaped trough on a noninclined platform over which the compression wheel rolls. A steady even flow of intravenous fluid administration as given by the new clamp is highly desirable, particularly when medications, such as vasopressors, must be delivered at a precise rate.