The work described in this chapter is a synthesis of recent instructional cognition research implications for fundamental educational multimedia theory. Most of the research described here has been conducted in the Cognitive Load Theory context. The leading research group in this area is located at the University of New South Wales, in Sydney, Australia, and a complementary cognition research program is based at the Open University of Netherlands. The work emanating from these groups and allied efforts elsewhere has significant implications for multimedia use in various educational contexts. In this chapter the structure of human cognitive architecture will be described from an information processing perspective. Then the cognitive load theory will be introduced. The implications of multimodal experiments for multimedia instruction will be derived in the cognitive load theory context. The interaction of multimodal instruction and material complexity or element interactivity plus prior knowledge will be considered. Then the research on the instructional effects of moving images and sound will be discussed from a cognitive perspective. Methods for alleviating the visual search on complex multimedia screens employing focusing or linking strategies will be described. Guidelines for the effective design and use of educational multimedia in a global context will be noted in each section. Finally general issues of future research interest will be discussed. The objectives of this chapter are to suggest a theoretical foundation for multimodal multimedia instruction, and to distil from the relevant cognition research a number of practical implications for educational multimedia planning, design and use.