Background: Injections are the main factors provoking pain, fear, and anxiety among hospitalized children. The purpose of this study is investigating the Effects of picture book on Reducing Anxiety Caused by Intravenous Catheterization among School-aged Children. Methods: In this randomized control trial study, seventy 6-12 year-old children were randomly assigned to either intervention or control group. Data was collected from 70 patients at Pediatric Emergency Room in the central Hospital in Bushehr- Iran during the summer and autumn, 2017. The subjects’ anxiety was evaluated before, during, and after the procedure by using Observation Scale of Behavior Distress instrument. Chi-square, Mann-Whitney and Wilcoxon tests were used for data analysis. Results: The mean anxiety scores of the intervention group was significantly less than those of control group after intervention. In addition, a significant difference was observed before and after the intervention in terms of anxiety levels. Conclusions: The school-aged children’s orientation on the intravenous catheterization and serum infusion play a significant role in controlling and reducing their anxiety during and after the intervention. Based on the result we suggested using the picture book to reduce the children anxiety before Intravenous Catheterization. Keywords: anxiety, pediatric, Intravenous Catheterization, education, picture book Trial registration: Current Controlled Trials: IRCT2017041712830N22). 2017-05-29