The initiation of formal science education provides an opportunity to investigate how age-related language and reading skills respond to the challenge of science literacy (SL) performance. SL in early primary schools refers to the understanding and application of scientific core ideas and practices for informed decision-making. Studies revealed that high levels of singular reading or language skills correlate with better SL performance in school settings. However, it is essential to explore how nuanced words and textual reading skills relate to SL performance for early primary learners. One hundred ninety-three Hong Kong second graders were assessed on word reading, reading comprehension, vocabulary, nonverbal reasoning, and SL. The hierarchical regression model shows that word reading and reading comprehension are significant predictors of SL, controlling for nonverbal reasoning and vocabulary. Further, mediation analysis reveals that reading comprehension significantly mediates the effect of word reading on SL at grade 2, suggesting a shared reading-SL cognitive process. A tailored early elementary school literacy instruction is a promising way to enhance SL development among young learners. Copyright © 2024 Informa UK Limited, trading as Taylor & Francis Group.