Stringent CAFÉ regulations along with technological advances in materials, high-pressure fuel injection and complex turbo charging systems have rekindled interest in the area of Diesel engines for passenger vehicle applications. A modern Diesel engine is not only clean and quiet but also allows comparable drivability relative to gasoline engines with considerable improvements in fuel economy. However the current generation diesel engine is a complex system. It is not uncommon to find features like Variable Geometry Turbo charging (VGT), Exhaust Gas Recirculation (EGR) and High Pressure Common Rail (HPCR) fuel injection. In this paper we discuss the design of a multivariable controller for the VGT-EGR system for intake flow regulation. Control design is carried out under the sliding mode framework.