Lung tumors are extremely rare in the pediatric population, comprising only 0.2% of all malignancies in children. Among them, mucoepidermoid carcinoma (MEC) is even rarer with a reported frequency of 0.1% to 0.2%. MEC is defined by the World Health Organization as a tumor characterized by a combination of mucus-secreting, squamous, and intermediate cell types. We describe the case of a 4-year-old girl who presented with a history of intermittent fever and nonproductive cough of 1-month duration after foreign body aspiration. The chest X-ray showed complete collapse of the left lung. After removal of the foreign body, the lung expanded well after. However, the control chest X-ray done after 5 days showed again complete collapse of the left lung. The biopsy specimen taken during bronchoscopy confirmed the diagnosis of low-grade MEC. Fluorescence in situ hybridization (FISH) confirmed the presence of MAML2 rearrangement. Complete surgical resection with preservation of lung parenchyma was performed. No adjuvant therapy was needed. Repeat bronchoscopy was performed 2 months after surgery and showed no recurrence of the tumor. In conclusion, a remote chest X-ray after removal of a foreign body is necessary to avoid missing a rare serious underlying disease such as MEC. According to the size and the location of the tumor, complete surgical removal is sufficient without additional treatment in case of low-grade tumor. The presence of MAML2 rearrangement confers a favorable outcome and may have long-term implications for the clinical management.