The purpose of this study is to investigate the effect of factors related to schools and teachers on mathematics achievement of Malaysian students in the Trend International Mathematics and Science Study conducted in 2003. A total of 150 schools were involved in the study and these schools were selected at random using simple random sampling from all secondary schools in Malaysia. This study employed a uni-variate analysis such as t-test or ANOVA to investigate the differences in mathematics achievement among groups. It was found that students taught by female teachers, participating in developing mathematics contents and mathematics curriculum, having few or no limitation on instruction, spent less time in reviewing homework and more on working problem on their own, students coming from economically less disadvantaged homes, good perception on the school climate and good class attendance had significantly higher mathematics achievement.