This article reports a quasi-experimental study on the effects of multimedia teaching and learning in English Literature--a subject which places high cognitive load on students. A large-scale study was conducted in 4 high-achieving secondary schools to examine the differences made to students' learning and performance by the use of multimedia and to relate this to different kinds of multimedia. Statistical significance and effect size calculations indicated that the equivalent of one grade level in General Certificate of Secondary Education (GCSE) was associated with the use of advanced and integrated multimedia, and that this was stronger than the effects of schools and sex of the students. It was found that advanced multimedia software eased cognitive overload, particularly in the area of intrinsic cognitive load. Limitations of the study are drawn, including the needs to examine process variables and learner-related variables. Conclusions and implications for further research and for enhancing teaching and learning with multimedia are made. (Contains 9 tables.)