The purpose of this study is to investigate the effect of using computer-based instruction on special education students' performance in mathematics in Al Amal School in Amman. The researcher followed the equivalent pre/post T test two group designs. The sample of this study consisted of 149 special education students. The subjects of the study were distributed into two groups. The experimental groups were taught using computer-based instruction while the control groups were taught using the traditional way. Descriptive statistical analyses were used (means and standard deviation) for the pre and post- tests of students' mathematics test. Comparison statistical methods were used (Two Way ANOVA) analysis of variance to make a comparison between the control and the experimental groups and gender variable (male and female). The findings of the study indicated that there were statistically significant differences in the post- test between the two groups in favor of the experimental group, and there was no statistically significant difference in the students' performance due to gender or to the interaction between gender and group.