This study, drawing on data from the third cycle of the Program for International Student Assessment (PISA) and employing three-level hierarchical linear modeling (HLM) as an analytic strategy, examined the relations of inquiry-based science teaching to science achievement and dispositions toward science among 170,474 15-year-old students from 4780 schools in 54 countries across the globe. The results of the HLM analyses, after accounting for student-, school-, and country-level demographic characteristics and students' dispositions toward science, revealed that inquiry-based science teaching was significantly negatively related to science achievement. In contrast, inquiry-based science teaching was significantly positively associated with dispositions toward science, such as interest in and enjoyment of science learning, instrumental and future-oriented science motivation, and science self-concept and self-efficacy. Implications of the findings for policy and practice are discussed.