We examined the developmental relations between knowledge of reading strategies and reading comprehension in a longitudinal study of 312 Dutch children from the beginning of fourth grade to the end of fifth grade. Measures for reading comprehension, reading strategies, reading fluency, vocabulary, and working memory were administered. A structural equation model was constructed to estimate the unique relations between reading strategies and reading comprehension, while controlling for reading fluency, vocabulary, and working memory. The results showed that there was a unique effect of reading strategies on reading comprehension, and also of reading comprehension on reading strategies.