To explore the wider educational environment included in the dynamic model of educational effectiveness, this paper reexamines the association between student achievement and two national culture dimensions: Monumentalism-Flexibility and Collectivism-Individualism. Using Programme for International Student Assessment (PISA) 2018 data of 317,127 students, 12,058 schools, and 41 countries, we evaluated three-level regression models controlling for students' socioeconomic status, gender, and grade; school's average socioeconomic status; and countries' wealth. The results of the multilevel regressions show significant negative associations of the two culture dimensions with student achievement in mathematics, science, and reading. However, our models indicate that Monumentalism-Flexibility is a better predictor of student achievement in mathematics and science, and that there is variation in effect sizes across domains. Implications for educational effectiveness research are drawn.