Readers' rhetorical competence is related to reading comprehension and moderates the impact of rhetorical devices in expository texts. In this cross-sectional study, we examine the differences in four measures of rhetorical competence (knowledge of anaphors, organizational signals, refutations, and a total score) in grades three through to six, we determine its contribution to expository text comprehension after controlling the effect of a wide set of linguistic and cognitive variables, and we study whether this contribution is moderated by grade or any of our control variables. First, although we found evidence for some level of rhetorical competence at early ages, data suggest that rhetorical competence development takes many years. Second, we found that knowledge of some rhetorical devices is acquired before knowledge of others. Finally, rhetorical competence was a unique predictor of expository text comprehension, and its influence was evident regardless of grade and all of the control variables. Most research on rhetorical competence concerns students at the end of the primary school or older. This is surprising given that, typically from third grade, children are expected to learn from expository texts across a wide range of subject matter (Best et al., 2008). For this reason, we conducted a cross-sectional study of Spanish students to determine how rhetorical competence develops and its role in the comprehension of expository texts during the elementary school years. The aims of this study were: (1) to describe Spanish students' rhetorical competence from grade three (8-9 years) to six (11-12 years), (2) to determine whether rhetorical competence makes a unique contribution to children's comprehension of expository text in this age range, Rhetorical competence and expository text comprehension in primary 4 above and beyond variables known to be strongly related to comprehension (namely word decoding, integration/inference skills, prior knowledge, and working memory), and (3) to examine whether the contribution of rhetorical competence to expository text comprehension was moderated by grade, or the other variables outlined above. 1.1. Rhetorical devices and rhetorical competence Rhetorical devices are signals that work as ''potential processing instructions'' for understanding the meaning of a discourse without affecting its organization or