This article begins by defining the construct of reading fluency, and then traces the roots of reading fluency instruction back to the nineteenth century including the common classification of text difficulty as offered by Emmett Betts (1943). The article then reviews selected aspects of the research supporting reading fluency instruction. Many researchers have reported on a significant relationship between fluent reading and comprehension. The manuscript discusses these findings along with new research suggesting the importance of foundational skills in achieving proficiency on state-wide reading assessments. We then discuss the various reading processes necessary for rapid word identification which is a prime ingredient for fluent reading. The review concludes with a discussion of fluency assessment and a call to assess phonemic awareness, letter-sound correspondence, word reading, and fluency for proper development.