The authors of this article investigate the economic knowledge of Czech high school students using a database of 18,589 participants from the 2019 to 2020 Czech Economics Olympiad. Czech high school students show solid comprehension of basic economic concepts and principles of international economics but understand substantially less about microeconomic and macroeconomic theory. The authors demonstrate that some prevalent features of students' economic knowledge found in other countries are also present in the Czech Republic, including a gender gap. Their analysis confirms problematic aspects of the Czech education system identified in prior studies, including large differences in education quality across types of schools and regions.