After more than two decades of intensive research, Sol MOSFETs technology offers significant advantages in the performance of many IC products and provides a viable solution for extending Si devices in the nanometer range exploiting ultra-thin silicon layers. A key advantage of Sol versus bulk MOSFETs is the opportunity of controlling short channel effects without increasing the channel doping, thus preserving high carrier mobility. In this paper we discuss the experimental characterization of electron mobility in ultra-thin Sol MOSFETS and the latest improvements in understanding the physical scenario underlaying the experimental results. (C) 2004 Elsevier Ltd. All rights reserved.