Abstract: An arm restraint for temporarily restraining a patient's arm while drawing either venous or arterial blood is described. The restraint includes a rigid member with a concave cross section to accept an arm from the upper part of the arm to below the wrist. Adjustable and removable straps are at each end of the rigid member with securing straps attached through slots in the rigid member substantially in the middle of the rigid member. The securing straps can be used to attach the arm restraint to a bed rail, a blood collecting chair or the like. Spring clips are attached to the underside of the rigid member to attach a blood collecting tray. An open ended slot is available at one end of the rigid member through which a tourniquet passes and continues around the patient's upper arm.