No higher-order skill will be more important for pupils to develop in the twenty-first century than critical thinking. Schools should integrate it into their curricula, thereby allowing students to acquire new skills in preparation for a dynamic and rapidly changing labour market. Educators, psychologists, and philosophers agree on the importance of critical thinking, but there is a lack of agreement on what the concept entails and on how it should be taught. It is against this background that the present study examines primary-school teachers' perceptions of teaching strategies aimed at stimulating pupils' core critical-thinking skills. Twenty-one teachers working in European Schools in Brussels were questioned by means of semi-structured interviews, and the results showed the importance of group discussion, cooperative learning, brainstorming, and debate to teaching practice aimed at promoting critical thinking. This research contributes to defining a framework in innovative teaching methods for promoting critical thinking.