Endobronchial foreign body aspiration is a rare occurrence in adults, with a higher incidence in children. However, the possibility of such foreign body aspiration should not be overlooked in adult patients presenting with recurrent pneumonia symptoms, particularly when antibiotic treatment is ineffective. The diagnosis of occult endobronchial foreign body aspiration is challenging and requires a high degree of clinical suspicion, as it may not be associated with a history of aspiration. In this report, we present a case of recurrent pneumonia persisting for over two years, which was eventually diagnosed as an endobronchial foreign body due to occult pistachio shell aspiration. The foreign body was successfully removed through bronchoscopy. The diagnostic workup for recurrent pneumonia, including imaging and bronchoscopy, and the therapeutic management of endobronchial foreign body aspiration are discussed in detail. This case highlights the importance of considering endobronchial foreign body aspiration as a potential diagnosis in adult patients presenting with recurrent pneumonia, even in the absence of a history of aspiration. Early recognition and prompt intervention can prevent potential complications, including bronchiectasis, atelectasis, and respiratory failure.