Inflammatory myofibroblastic tumor (IMT) is the most frequent primary lung tumor in children and it may be locally aggressive. The management of a locally advanced pulmonary IMT in an 18 month-old female child is presented.A left pulmonary mass was incidentally found on the computerized tomography (CT) scan of a child with persistent systemic inflammatory syndrome. Biopsy confirmed the diagnosis; after preoperative corticotherapy, left pneumonectomy was performed. The pericardium and left atrium were invaded and resected, requiring pericardial reconstruction. There is no relapse at four years of follow-up.Steroids play a role in tumor size reduction, but marginal resection is the gold standard. Extended approaches are feasible and often required in advanced cases.