This paper examines differences in mathematics achievement among eighth-grade students using a secondary analysis of the data. The students, who are from Malaysia, had participated in the Trend International Mathematics and Science Study (TIMSS) 1999. A series of school, home, demographic and socio-economic variables were used to investigate the differences in the mean student mathematics scores. Evidence from the data shows that gender, the language spoken at home, expected educational level, family background, and home educational resources and aids have a significant influence on the students' level of mathematics achievement.