Purpose This study aimed to examine the effect of exercise on static and dynamic balance in children with cerebral palsy (CP) using a Swiss ball. Methods The subjects(n=7) underwent the Independent Standing Time and Modified Timed Up and Go tests before and after one treatment session with a Swiss ball. We compared these data to specifically determine the effect of the intervention without it being influenced by other variables. Results We found a significant increase (p<0.05) in the Independent Standing Time with eyes opened and closed after the intervention. We also found a significant difference between the Modified Timed Up and Go test before and after intervention. Conclusion Thus, exercise with a Swiss ball can improve static and dynamic balance in subjects with CP diplegia.