The Australian SKA Pathfinder (ASKAP) is a 1% Square Kilometre Array (SKA) pathfinder radio telescope, comprising of 36 12-metre diameter reflector antennas, each with a Focal Plane Array consisting of approximately 100 dual-polarised elements operating at centimetre wavelengths and yielding a wide field-of-view (FOV) on the sky of about 30 square degrees. ASKAP is currently under construction and will be located in the remote radio-quiet desert Midwest region of Western Australia. It is expected to be fully operational in 2013. Key requirements for the ASKAP control system include: control and monitoring of widely distributed devices, handling of a large number of monitoring points (< 150, 000), accurate time synchronisation and remote semi-automated operations. After evaluating several software technologies we have decided to use the EPICS framework for the Telescope Operating System and the Internet Communications Engine (ICE*) middleware for the high-level control message bus. This paper presents a preliminary design of the ASKAP control system as well as describing why we have chosen EPICS and ICE and how both technologies fit in the overall ASKAP software architecture.