This study was conducted to understand the effect of student-, classroom-, and school-level factors on the science performance of 8th-grade Taiwanese students in the Trends in International Mathematics and Science Study (TIMSS) 2011 by using multilevel analysis. A total of 5,042 students from 153 classrooms of 150 schools participated in the TIMSS 2011 study, in which they were required to complete questionnaires. A 3-level multilevel analysis was used to assess the influence of factors at 3 levels on the science performance of 8th-grade Taiwanese students. The results showed that the provision of education resources at home, teachers’ level of education, and school climate were the strongest predictor of science performance at the student, classroom, and school level, respectively. It was concluded that the science performance of 8th-grade Taiwanese students is driven largely by individual factors. Classroom-level factors accounted for a smaller proportion of the total variance in science performance than did school-level factors.