Students commonly multitask while studying. The ubiquitous use of laptops and computers has facilitated this phenomenon and even changed the nature of multitasking in studying environments. Interruptions have an undeniable presence in these everyday studying environments and there are growing concerns about their potential to disrupt both performance and the learning process. Since interruptions are unavoidable, it is useful to identify the features that make some interruptions more disruptive than others. This study investigates how interruption task complexity affects student multitasking, using a novel computer-based multitasking paradigm comprising four subtasks (article comprehension, email-typing, video dictation, figure-copying). The number of mental operators required for an interruption task will be used to define interruption complexity. 36 undergraduates from the University of Edinburgh were randomly assigned to three different interruption groups. The control group was not interrupted, the easy interruption group was given an easy picture-naming task, and the difficult interruption was given a difficult picture-naming, defining and decision-making task. Results of a Kruskal-Wallis test revealed no differences in overall multitasking performance between the groups. However, a three-way repeated measures ANOVA demonstrated that there were significant declines in post-interruption compared to pre- interruption performance. Furthermore, this effect was greater for the group that received difficult, as opposed to easy interruptions, supporting the hypothesis that complex interruptions are more disruptive than simple interruptions. Taken together, results from this study suggest that the disruptive impact of interruptions is very brief and that students are able to compensate for interruptions during multitasking.