A B S T R A C TReading and writing are critical to students' success in and outside of school. Because they draw on common sources of knowledge and cognitive processes, involve meaning making, and can be used conjointly to accomplish important learning goals, it is often recommended that reading and writing should be taught together. This meta-analysis tested this proposition by examining experimental intervention studies with preschool through high school students to determine whether literacy programs balancing reading and writing instruction strengthen students' reading and writing performance. To be included in this review, no more than 60% of instruction could be devoted to either reading or writing. As predicted, these programs improved students' reading, resulting in statistically significant effects when reading measures were averaged in each study (effect size [ES] = .39) or assessed through measures of reading comprehension (ES = .39), decoding (ES = .53), or reading vocabulary (ES = .35). The programs also statistically enhanced writing when measures were averaged in each study (ES = .37) or assessed via writing quality (ES = .47), writing mechanics (ES = .18), or writing output (ES = .69). These findings demonstrated that literacy programs balancing reading and writing instruction can strengthen reading and writing and that the two skills can be learned together profitably. R eading and writing are essential for success in school, at work, and in everyday life. Students use reading to analyze and acquire information presented in online text, books, and other printed materials (Berman, 2009), whereas writing is used to sharpen and promote students' learning and assess what they know (Bangert-Drowns, Hurley, & Wilkinson, 2004;Graham, 2006). Reading and writing serve multiple purposes in white-collar and blue-collar jobs today (Greene, 2000; National Commission on Writing for America's Families, Schools, and Colleges, 2004, 2005). This includes, but is not limited to, reading and writing to acquire and share information, communicating with other employees and the public at large, tracking and recording pertinent information, and developing reports and disseminating policies. Reading and writing also permeate day-to-day life, as Facebook, texting, tweeting, blogging, emailing, and other forms of digital literacy are prevalent.Despite the importance of reading and writing to life in the 21st century, there is considerable concern that many youngsters do not acquire the literacy skills needed to be successful in an increasingly digital and information-based world (e.g.