To promote the academic success of middle school students, the authors examined the effects of computer uses on mathematics self-efficacy and mathematics performance of students, paying focused attention to immigrant students. They analysed the effects of computer use for schoolwork and gaming of middle school students applying a Structural Equation Modeling (SEM) to Trends in International Mathematics and Science Study (TIMSS) USA. The results showed that when students frequently used computer for schoolwork, they revealed high mathematics self-efficacy, which in turn led to high mathematics performance. On the other hand, the students that used computer for gaming frequently indicated low mathematics self-efficacy and mathematics performance. The authors' study results highlight the importance of guiding students to use computers properly, which is directly and indirectly associated with students' self-efficacy and performance in mathematics.