Objective: The purpose of this research is to compare working memory in children with attention/deficit hyperactive disorder (ADHD) with the normal peers. The participants included 11 boys with and 11 boys without ADHD ageing 6 to 12 years. Method: ADHD was diagnosed utilizing a psychiatric interview, Conners parents rating scale, and CSI-4 inventory. All children were matched in IQ by Raven intelligence test. Kim Carrad visual memory test and story recall test were used to asses working memory. Results: Using t-test for independent groups, significant differences were observed between the performance of ADHD and normal children in Kim Carrad visual memory test and story recall test. Performance of children with ADHD in verbal and visual working memory tests was worse than normal children. In addition, visual processing information in ADHD children was slower than normal children. Conclusion: Weakness in working memory in ADHD children may be related to some deficits in inhibition. This research can support those theories that relate ADHD and working memory.