Résumé : Inflammatory myofibroblastic bladder tumors are rare benign tumors, with fusiform cells, that preferentially affect children. They are part of the differential diagnosis of tumors of the bladder and more generally of sarcomas of the soft tissues. They are classified as intermediate malignancy tumors with a low risk of metastasis and a potential for local recurrence variable, according to its primary site: low for pulmonary sites and much more important for extra-pulmonary locations. A case study of an 8-year-old child with macroscopic hematuria and dysuria is described. The assessment revealed an intra-vesical mass. Histology and immunohistochemistry allow confirming the diagnosis of inflammatory myofibroblastic tumor and excluding rhabdomyosarcoma. Surgery is the best treatment.