The purpose of this study was to examine the connection between sixth graders' cognitive tool use and the cognitive processes they engage in as they solve a complex problem in a hypermedia learning environment. The three research questions were: (1) Which cognitive tools are used for which cognitive processes? (2) Is there a relationship between the extent of students' engagement in cognitive processing and their cognitive tool use? and (3) Are there any differences in cognitive tool use and performance scores between students who are engaged in different patterns of cognitive processing? The findings showed that different cognitive tools were used for different cognitive processes, and the degree of engagement in cognitive processing was positively related to the frequency of tool use. These results indicate that there is a connection between cognitive tool use and cognitive processing. In addition, tool use patterns reflected different characteristics of the learners (information processing versus metacognition oriented). Students who were more metacognitively oriented were more consistent in their tool selection, while students who were more information processing oriented were more action oriented in performing the tasks. However, there was no difference in the diversity of tool use or the performance scores between the two groups of students.