Control of the upper extremities of a sedated or anesthetized patient can be a cumbersome and difficult problem during hip spica cast application. To overcome this, we developed a simple technique to control the upper extremities without placing the neurovascular structures under tension while allowing easy venous access for the anesthesia personnel. Use of a simple armboard made of supplies commonly available in the cast room has made this possible. The construction and clinical use of this armboard is described. It has been used successfully for > 12 months at the authors' institution with no untoward effects.