The OECD Programme for International Student Assessment (PISA) examines not just what students know in science, reading and mathematics, but what they can do with what they know. This report is the product of a collaborative effort between the countries participating in PISA, the national and international experts and institutions working within the framework of the PISA Consortium, and the OECD Secretariat. Results from PISA show educators and policy makers the quality and equity of learning outcomes achieved elsewhere, and allow them to learn from the policies and practices applied in other countries. "PISA 2015 Results (Volume I): Excellence and Equity in Education," is one of five volumes that present the results of the PISA 2015 survey, the sixth round of the triennial assessment. It summarises student performance in science, reading and mathematics, and defines and measures equity in education. It focuses on students' attitudes towards learning science, including their expectations of working in science-related careers. The volume also discusses how performance and equity have evolved across PISA-participating countries and economies over recent years. This volume contains the following chapters: (1) Overview: Excellence and Equity in Education; (2) Science Performance among 15-Year-Olds; (3) Students' Attitudes towards Science and Expectations of Science-Related Careers; (4) Reading Performance among 15-Year-Olds; (5) Mathematics Performance among 15-Year-Olds; (6) Socio-Economic Status, Student Performance and Students' Attitudes towards Science; (7) Immigrant Background, Student Performance and Students' Attitudes towards Science; and (8) What PISA 2015 Results Imply for Policy. Contains the following annexes: (1) PISA 2015 Technical Background; (2) PISA 2015 Data; (3) PISA 2015 Test Items; and (4) The Development and Implementation of PISA: A Collaborative Effort. Individual chapters contain references.