Constructing meaning from science texts relies not only on comprehending the words but also the diagrams and other graphics. The goal of this study was to explore elementary students' perceptions of science diagrams and their skills related to diagram interpretation. 30 students, ranging from second grade through middle school, completed a diagram sorting task and a follow-up short interview regarding four versions of a water cycle diagram selected from school science texts. Additionally, 6 students participated in follow-up longer interviews about diagram interpretation. Results indicate that students valued diagrams with high levels of organization and significant amounts of information. However, students were frequently confused regarding specific conventions of diagram design, such as arrows, and did not fully understand the function of diagrams in science texts. Implications for teachers include methods for assessing students' diagram interpretation skills and explicit instruction in analyzing diagrams. (Contains 4 figures.)