A two dimensional-hydrodynamic model is carried out to predict the performance of short gate length power field effect transistors based on III-V semi-conductor systems. The model is based on the conservation equations, deduced from the Boltzmann transport equation, solved in their whole form by taking temporal and spatial variations in carrier momentum into account. This model is well suited to get accurate predictions for power devices having various gate recess topologies. Results are performed for devices with different gate lengths and compared with those obtained from simplified models. For gate lengths shorter than 0.5 mum, a drop in the overshoot velocity phenomenon involves a better estimation of the characteristics of the device. (C) 2003 Elsevier Science Ltd. All rights reserved.