Reading is critical to students' success in and out of school. One potential means for improving students' reading is writing. In this meta-analysis of true and quasi-experiments, Graham and Herbert present evidence that writing about material read improves students' comprehension of it; that teaching students how to write improves their reading comprehension, reading fluency, and word reading; and that increasing how much students write enhances their reading comprehension. These findings provide empirical support for long-standing beliefs about the power of writing to facilitate reading. (Contains 6 tables.)