The Program for International Student Assessment (PISA) is a system of international assessments that allows countries to compare outcomes of learning as students near the end of compulsory schooling. PISA core assessments measure the performance of 15-year-old students in mathematics, science, and reading literacy every 3 years. Coordinated by the Organization for Economic Cooperation and Development (OECD), PISA was first implemented in 2000 in 32 countries. It has since grown to 65 education systems in 2012. PISA's goal is to assess students' preparation for the challenges of life as young adults. PISA assesses the application of knowledge in mathematics, science, and reading literacy to problems within a real-life context (OECD 1999). Mathematics was the major subject area in 2012, as it was in 2003, since each subject is a major subject area once every three cycles. In 2012, mathematics, science, and reading literacy were assessed primarily through a paper-and-pencil assessment, and problem solving was administered via a computer-based assessment. In addition to these core assessments, education systems could participate in optional paper-based financial literacy and computer-based mathematics and reading assessments. The United States participated in these optional assessments. This report presents performance on PISA 2012 in mathematics, science, and reading literacy from a U.S. perspective. Results are presented for the 65 education systems, including the United States, that participated in PISA 2012 and for the three U.S. states--Connecticut, Florida, and Massachusetts--that participated as separate education systems. These three states opted to have separate samples of public-schools and students included in PISA in order to obtain state-level results. In this report, results are presented in terms of average scale scores and the percentage of 15-year-old students reaching selected proficiency levels, comparing the United States with other participating education systems. For proficiency levels, results are reported in terms of the percentage reaching level 5 or above and the percentage below level 2. Higher proficiency levels represent the knowledge, skills, and capabilities needed to perform tasks of greater complexity. At levels 5 and 6, students demonstrate higher level skills and may be referred to as "top performers" in the subject. Conversely, students performing below level 2 are below what the OECD calls "a baseline level of proficiency, at which students begin to demonstrate the literacy competencies that will enable them to participate effectively and productively in life" (OECD 2010, p. 154). This report also presents U.S. trends over time in mathematics, science, and reading literacy, and overall results for the computer-based mathematics and reading assessments. Results for the problem-solving and financial literacy assessments will be released in 2014. Appended are: (1) Methodology and Technical Notes; and (2) International and U.S. Data Collection Results. (Contains 9 tables, 3 figures, 9 footnotes, and 3 exhibits.) [This report was prepared for the National Center for Education Statistics under Contract No. ED-IES-10-C-0047 with Westat.]