The study investigates the use of different multimedia instructional design formats on learning. Undergraduate students from the College of Education at a public university in the United Arab Emirates were randomly assigned to groups corresponding to six instructional design formats, namely; Listen Only, Read Only, Read+ Listen, Listen + Graphics, Read + Graphics, or Listen + Read + Graphics. A pretest was administered to test student prior knowledge of a lesson on lightning. During acquisition, students received instructions specific to the instructional format they were assigned to. For example, students in the Read Only group received written materials only while those in the Listen Only group received auditory materials only. Students were then given a test task related to the materials that were presented during acquisition. Based on cognitive load theory, it was hypothesized that different instructional design formats will result in different performances. In other words, at least some students would not benefit from multimedia learning materials because of extraneous cognitive load that was caused by the instructional format in which the material was presented. The results of an analysis of variance yielded statistically significant differences in performance between the six groups with the read only group scoring highest. (Contains 3 tables and 1 figure.)