A considerable body of empirical research supports the belief that extensive reading is an effective way for second language learners to develop greater reading fluency. However, recent research indicates that extensive reading alone is not the most effective way to promote greater fluency. In this presentation I first review theories of fluency development proposed by cognitive psychologists and synthesize the key ideas in those studies. This synthesis produces a short list of desirable characteristics of fluency-enhancing reading tasks. I then consider how well extensive reading and other types of reading activities have those desirable characteristics, in what ways these activities appear to be lacking, and how their potential weaknesses can be addressed. This analysis shows that although extensive reading is an indispensable part of a fluency-based reading course, fluency development can be enhanced by using supplementary reading tasks.