This systematic review analyzed the relationship between emergent writing, alphabet knowledge and vocabulary and children's words/pseudowords reading and writing performances in Portuguese literacy acquisition. A systematic search was conducted in the PsycInfo and BVS databases (2000-2024). After the selection process, 11 studies were included in the review. The review identified significant associations between alphabet knowledge and vocabulary performances and words/pseudowords reading and writing performances. A schooling effect was observed: the strength of associations between emergent literacy and written language skills was moderate to strong among preschool and first-grade students, decreasing from second grade onward. Differences in associations were analyzed based on the type of skill in emergent literacy assessment and the type of stimulus in reading and writing evaluation. The findings highlighted the need for further investigation to understand the specific contributions of emergent literacy skills to literacy acquisition in Portuguese. Study implications and future directions were discussed.