This study explored the differential contribution of cognitive and motivational factors on the comprehension of an expository text in secondary school students. One hundred and fifty-five 7th and 8th grade students were assessed in prior knowledge, inferences, metacognition, reading motivation, topic interest, and reading comprehension of history text. According to the multiple regression analyses, inferences and self-efficacy uniquely contributed to reading comprehension. Intrinsic motivation moderated the association between metacognition and reading comprehension of a history text. These results confirm that the final outcome of reading comprehension greatly depends on a complex interplay between cognitive and motivational variables.