We investigated the relationship between four inquiry-based teaching practices (use of: (1) models or applications, (2) hands-on activities, (3) interaction and (4) independent investigations) and science achievement for 15-year olds across eight countries participating in the Program for International Student Assessment (PISA) 2006. Within each country, we find consistent evidence that students reporting more frequent use of independent investigations have lowered achievement in science; however, students reporting higher frequency with which science lessons emphasize models or applications tend to have higher achievement. Evidence regarding the effectiveness of hands-on activities and interaction was mixed. Our findings highlight the importance of lessons that have applications to the real world and that have investigations which are directed and scaffolded versus purely discovery-based.