Purpose: The purpose of this article is to discuss reading comprehension deficits in adolescents in relation to their word reading skills and lexical and syntactic development. Although reading comprehension strategies (e.g., "Find the main idea") are often recommended, it is argued that before these can be effective, students' underlying language deficits should be addressed. Method: Data from a longitudinal study are analyzed to determine the relationship between reading comprehension, word reading, and lexical and syntactic development in adolescents. Results: The findings indicate that poor reading comprehension in adolescents is predicted by concurrent deficits in word reading ability, lexical development, and syntactic development. Conclusion: When poor comprehension is accompanied by deficits in word reading ability and/or lexical and syntactic development, intervention should target the underlying areas of deficiency. Studies designed to improve reading comprehension in adolescents are needed.