Although the empirical relationship between general intelligence and academic achievement is well established, that between specific cognitive abilities and achievement is less so. This study investigated the relationships between specific Cattell-Horn-Carroll (CHC) cognitive abilities and reading comprehension across a large sample of children (N = 835) at different periods of reading development (grades 1-5). Results suggest select cognitive variables predict reading comprehension above and beyond basic reading skills. However, the relative importance of specific cognitive abilities in predicting reading comprehension differs across grade levels. Further analyses using mediation models found specific cognitive abilities mediated the effects of basic reading skills on reading comprehension. Implications for the important and dynamic role of cognitive abilities in predicting reading comprehension across development are discussed.