Learners gain deep understanding in multimedia-based learning environments when they receive worked examples in initial cognitive skill acquisition. This is at least true if classic multimedia design principles and other instructional principles are taken into account. This chapter elaborates on the worked examples principle. More specifically, it first illustrates the tight connections between multimedia learning and worked examples by several exemplary cases before reporting about findings on the effectiveness of worked examples in multimedia learning. The effectiveness of worked examples is then theoretically explained. Furthermore, instructional principles are derived from findings on factors that moderate worked example effects. Finally, important questions to be addressed in further research (e.g., analyzing long-term effects in classroom learning) are proposed.