Factor analysis and hierarchical linear modeling are employed to examine Program for International Student Assessment (PISA) 2003 data (with updates from PISA 2006 and the Trends in International Mathematics and Science Study, TIMSS 2007) regarding the effects on mathematics achievement in the United States of student-level variables including socioeconomic status (SES), gender, motivations, mathematics anxiety, self-related cognitions, and school-level variables including percentage of female students, number of mathematics activities, and student/mathematics teacher ratio. At the student level, SES, motivations, and self-related cognitions have positive relationships with students΄ mathematics achievement, while mathematics anxiety is negatively associated with mathematics achievement. At the school level, percentage of female students, number of mathematics activities, and student/mathematics teacher ratio do not significantly influence average school mathematics achievement. [ABSTRACT FROM AUTHOR]