The purpose of this research was to comparing the working memory performance in dyslexic and non-dyslexic students and investigating the effect of rehearsal on working memory performance in dyslexic children. The method of this research was quasi-experimental. Statistical sample of research consisted of fifteen students who were dyslexic and fifteen normal students were considered as a control group. All of them were studying at third grade. Both two group responded to the Working Memory Test Battery for Children (WMTB-C) (Pickering & Gathercole, 2001).Rehearsal performed on dyslexic group. As a result, normal students performed significantly better than dyslexics on working memory test. The effect of rehearsal on working memory performance was not significant.