Introduction: Teratomas are benign germ cell tumors composed of components from the ectoderm, mesoderm, and endoderm. While germ cell tumors account for 10-20% of anterior mediastinal masses, intrapulmonary teratomas (IPTs) are extremely rare. They typically occur in the third decade of life and may present as metastasis from gonadal tumors. This study reports a rare case of a mature IPT in the right middle lobe of the lung, initially misdiagnosed as pulmonary tuberculosis and aspergilloma. Case Presentation: A 17-year-old female presented with a 4-year history of cough with sputum and two episodes of hemoptysis. Despite negative tuberculosis tests, she was treated with anti-tubercular drugs and multiple antibiotics. Imaging revealed a 5.5-cm cavitary mass in the right middle lobe containing an aspergilloma. Surgical resection was performed, and the pathology confirmed a mature teratoma with aspergilloma colonization. The patient recovered well postoperatively and showed no signs of recurrence. Discussion: Teratomas are germ cell tumors rarely found in the lungs, with fewer than 100 cases reported globally. Diagnosis is challenging due to overlapping symptoms with other conditions such as tuberculosis. In this case, the presence of an aspergilloma further complicated the diagnosis. Complete surgical resection led to the patient's recovery. Conclusion: Mature IPTs with aspergilloma are extremely rare, and should be considered in the differential diagnosis of cavitary lung lesions. Early diagnosis and surgical resection are crucial for successful treatment.