This chapter begins with an outline of the processes needed for effective text understanding in skilled readers, and the levels at which problems in text comprehension might arise. This overview provides some relevant background for later discussion of how children’s comprehension can fail. We consider, in particular, the difficulties that children can have with reading, even when they are competent at single-word recognition. Although single word reading and comprehension skill are, in general, highly correlated, a substantial minority of children develop the former but not the latter skill.