INTRODUCTION Pleural effusion is a pathology resulting from overproduction of pleural fluid and decreased absorption. Transudative pleural effusions are caused by general alterations in formation and absorption, as in the case of cirrhosis or heart failure. Exudative pleural effusions are usually caused by local alterations that affect physiology, such as pneumonia, neoplasms or pulmonary embolisms. The origin of the fluid in the present clinical case comes from the presence of an infectious process located in the sub-mandibular region, due to poor hygiene and oral care of the patient, which leads to bacterial pneumonia, which evolves into empyema. CLINICAL CASE The clinical case is presented of a 43 year old male patient, attended in a hospital in the Amazon, belonging to the province of Morona Santiago-Ecuador, with a personal history of chronic alcoholism; and the presentation of a picture of pain in the oral cavity of moderate intensity, associated with purulent secretion of moderate quantity, which evolves unfavourably with non-productive cough and pleuritic pain. Complementary studies were carried out which revealed the presence of pleural empyema and submandibular abscess. EVOLUTION The patient was treated with broad-spectrum antibiotic therapy, vasoactive support management due to the presence of septic shock and management of his dental problems. In addition, radiographic and tomographic images were taken to confirm the patients critical clinical condition. Subsequently, the patient decided to request medical discharge to go to another private health unit of greater complexity. CONCLUSIONS Neck abscesses are the result of dental disorders which, if not treated immediately, are a strong predisposing factor for infections in other regions of the body through dissemination, such as the lung, mediastinum and pericardium. The different causes of empyema are of vital importance, because diagnosing the possible aetiologies of empyema can lead to a correct and more targeted management and treatment of the cause.