Introduces a dual-task approach to the direct measurement of cognitive load in multimedia learning, and presents empirical results of its implementation. After an introduction to cognitive load theory and its pertinence to instruction and multimedia learning, the measurement of cognitive load is discussed. Current approaches employing direct and indirect as well as subjective and objective methods are described before the new dual-task approach to measurement is presented. This computer-based method is described as a direct and objective measure that can overcome some of the shortcomings of the earlier methods. Experimental evidence supporting the suitability of the measurement technique in different instructional environments is provided. Differences in learning outcome were found to be related to different levels of cognitive load which in turn were induced by the different presentation formats of the learning material. The dual-task approach is concluded to be a direct and easily implemented method for the measurement of cognitive load in multimedia learning environments, and its shortcomings are discussed.