This paper reports the results of a study on mean value modeling and model predictive control of a turbocharged Diesel engine airpath. The objective of this study, and also in general the control of Diesel engines, is to increase the usefulness of the electronic engine control units by using effective control strategies, such as model predictive control. The system used in this study consists of a four stroke, four cylinder high speed Diesel engine, a Variable Geometry Turbocharger (VGT) and an Exhaust Gas Recirculation (EGR) system. A controller is designed to control the Mass Air Flow (MAF) and Manifold Absolute Pressure (MAP) by changing the positions of exhaust gas recirculation valve and varying the geometry of turbocharger. Simulations are developed to enable the system work at different setpoints and also to include the effects of disturbances and wrong model order.