Inflammatory myofibroblastic tumor of the carina and the main bronchus is a rare tumor. The authors report here on a case of a 4-year-old boy with an inflammatory myofibroblastic tumor at the carina and extending to the left main bronchus. He presented with fever and a cough of 2 months' duration. Preoperative assessment of the tumor revealed an intraluminal round mass arising from the carina and extending into the left main bronchus, and this caused near-total obstruction of the left main bronchus and the subsequent total collapse of the entire left lung. The complete resection of the mass with carinal reconstruction was successful. The tumor was a round mass measuring 1.5 x 1 cm. It had characteristic features of an inflammatory myofibroblastic tumor, namely, the proliferation of spindle-shaped fibroblasts and myofibroblasts.