This paper discusses the use of Mechanically Stabilized Earth (MSE) walls in ever increasing heights. Most MSE walls worldwide that exceed 20 meters high are constructed using metallic reinforcements in the reinforced volume. Design of tall MSE walls has much in common with design of lesser-height walls, but the performance of more detailed site investigations prior to design and the use of instrumentation monitoring during construction are critical to ensuring successful performance of these tall structures. Design features important to tall walls are described, and the paper cites several examples of completed tall MSE walls to demonstrate the international acceptance of such structures in major industrial and highway projects.