Research has shown that multimedia plays an important role in the development of the cognitive abilities of students. Therefore, the research objectives of this study were to find out what types of multimedia resources were present in selected school libraries in the Caribbean, as well as how these multimedia resources were used in instruction by school librarians, and to draw conclusions on teacher librarians’ perception of the effects that multimedia learning has on students’ cognitive ability. The sample consisted of 162 teacher librarians. A newly developed questionnaire was used to collect the data, which indicated that a variety of multimedia resources were used in these school libraries. Teacher librarians used these resources to create, for example, PowerPoint presentations, podcasts, Twitter feeds,  blogs and wikis, which were used in instruction. Based on the cognitive load theory, the teacher librarians perceived that the use of multimedia in instruction developed cognitive skills such as critical thinking and problem solving in students. It was recommended that teacher librarians include more web 2.0 tools in instruction to further develop students’ cognitive skills.