The paper presents an overview of research on working memory as a predictor of early school achievements. We contrast two main areas of research on the role of working memory in school achievements: the first concerns the structural model of working memory and the second focuses on executive functions. Then, we discuss the facet model of working memory as a promising approach merging the two research branches on working memory tasks as predictors of early school achievements. At the end we (...) present exemplary results of the research conducted on a national sample of six- and seven-year-olds in Poland, which indicates strong relation of working memory functions with the measures of competences in mathematics, reading, and writing. Additionally, the mediation analyses, with parents’ education as a covariate, indicate that the influence of age on achievements in math, reading, and writing in six- and seven-year olds is mediated by working memory functions. (shrink)