BACKGROUND: Treatment procedures are the most common sources of pain in children. Children with chronic diseases such as thalassemia experience many pains during painful procedures including at times of diagnosis, treatment and control of their disease. Several methods have been reported to reduce pain. Clinical professionals usually use distraction techniques to reduce pain. However, there is no agreement between them that which distraction technique is better for reducing pain. The aim of this study was omparing the effects of regular breathing exercise and making bubbles on the pain of catheter insertion in school age children.METHODS: This was a clinical trial on 60 children in the age range of 6 to 12 years, who were suffering from thalassemia and had a file in the Center for Thalassemia. Participants were randomly divided into two groups of experiment and control. Bubble making was performed for the first group and regular breathing exercise was performed for the second group. Data were collected using a demographic questionnaire, a scale for pediatric pain behavioral symptoms and Numeric Pain Rating Scale. Data were analyzed using descriptive (frequency, mean and standard deviation) and inferential statistics (ANOVA, Kruskal Wallis, and Mann Whitney U tests and Spearman correlation). RESULTS: The mean pain score based on the numerical scale was 5.60 ± 3.13 in the control group, 1.60 ± 1.75 in the bubble-making group and 1.85 ± 1.42 in the breathing exercise group. The mean score of behavioral pain symptoms was 3.80 ± 2.80 in the control group, 1.15 ± 1.13 in the bubble-making group, and 0.96 ± 0.75 in the breathing exercise group. Results showed a significant difference in the mean pain scores (based on numeric scale and pain behavior scale) between the control group and other groups after the injection, but the difference in the mean pain scores between the two groups of experiment after the injection was not significant. CONCLUSIONS: According to the results of this study, both distraction methods of regular breathing exercise and bubblemaking can reduce the pain of catheter insertion in children and since there was no difference between their effects, they can be used based on the individual child's interest.