OBJECTIVE To assess the diagnostic and therapeutic difficulties as well as the long-term complications of prolonged endobronchial foreign body retention. METHODS Between January 2000 and May 2021, 794 patients with suspected foreign body aspiration (FBA) were hospitalized in our department. A total of 12 patients with a delayed diagnosis of over 1 month were included. FBAs were confirmed by flexible or rigid endoscopy. A retrospective analysis of medical records was performed. RESULTS Six male patients and six female patients were hospitalized due to prolonged FBA. The average age was 6.90 years (range: 1-13 years). The average duration of the foreign body retention was 2.60 years (2 months to 9 years). A choking event was found in eight cases. Coughing and wheezing were the main symptoms and signs. A misdiagnosis of asthma was made for five patients. Two atypical clinical presentations led to diagnosis of endobronchial foreign body, unilateral pleurisy, and hemoptysis. We report one case of an occult foreign body externalized spontaneously through a pneumo-pleuro-cutaneous fistula. The most common clinical and radiological findings were of pneumonia and atelectasis. Computed tomography showed localized bronchiectasis in three patients. FBAs were removed with a rigid bronchoscope in eight cases. Other extractions were carried out with a flexible endoscope. The foreign bodies were most frequently of vegetable origin, such as seeds and peanuts. A granulation tissue was observed in seven cases. Bronchial stenosis and bronchiectasis are the most common late complications. Only one patient needed a surgical intervention. CONCLUSIONS FBA should always be considered in the differential diagnosis of chronic or recurrent respiratory diseases, even in the absence of a previous choking event. Clinical and radiological findings should be carefully evaluated for a possible FBA. Delay in diagnosis and treatment of FBA should be avoided in order to prevent complications. Open surgery may be required when lung abscess has occurred.