The present study is done to compare working memory in monolingual and bilingual children with special learning disability. Design of research was causal-comparative. Statistical society of the research was elementary students in Tehran and Javanroud in the 1392-1393 years. A number of 60 children including 30 (15 gilrs and 15 boys) monolingual (Persian) and 30 (15 gilrs and 15 boys) bilinguals (Kurdish-Persian) were recruited from special learning disability rehabilitation centers by accessible sampling. Data were collected with Wechsler intellectual scale for children-revised (shahim,1390) and Wechsler’s subscale of working memory test (WWM). To analysis of data, descriptive and inferential statistic methods including average, standard deviation, independent t-test and Friedman test were done and analyzed by Spss 16. Results show that there is significant differences in spatial working memory (p < 0.05, t=-2.17) and working memory (p < 0.05, t=-2.14) between monolinguals and bilinguals. There was no significant difference in the letter-number sequence (p>0.05, t=-1.09). Based on the findings of the present study, it can conclude that bilingualism is associated with better working memory functions in bilingual children with SLD.