This study investigates the concurrent and longitudinal relationships between polysemous word knowledge and reading comprehension among bilingual students (n = 107) followed from seventh to eighth grade. Standardized tests were used to measure decoding skills, broad vocabulary knowledge, and reading comprehension. Data about students' polysemous word knowledge were collected using the Polysemous Word Test, an assessment designed to investigate students' abilities to recognize the academic senses of words that also have casual, everyday meanings. The study provides longitudinal evidence that students' knowledge of the academic senses of familiar words contributes to their future reading comprehension. Results from hierarchical multiple regression analyses indicated that students with better polysemous word knowledge in seventh grade show higher levels of grade eight reading comprehension, controlling for grade seven reading comprehension and other skills, compared to students with weaker polysemous word knowledge. Reading comprehension was found to predict polysemous knowledge in both seventh and eighth grade as well as between seventh and eighth grade.