Motivational design theory complements instructional design theory and, when used together, both principles can affect learning, knowledge acquisition, and knowledge retention. In information literacy instruction, motivational design exists throughout the appropriate standards documents. However, there is limited current research on the best practices for using motivation in information literacy or library-based instruction. The existing research does indicate that librarians who deliver information literacy instruction attempt to implement motivational design theories such as Keller's ARCS model into their teaching, although often at a low level. Furthermore, studies of face-to-face and online library learning environments illustrate that using the ARCS model--and, more broadly, considering student motivation--can impact student learning and achievement. In considering how future information literacy instruction can be most effectively designed, expanding research on the meaningful inclusion of motivational design in information literacy instruction could help to shape this discipline's instructional significance, knowledge retention, and learning application.