Fusobacterium nucleatum is an anaerobic bacillus that is part of the oral microbiota and dental pla que. This can cause local and potentially remote infections, which are exceptional in pediatrics. Ob jective: To present the case of a patient with lung injury with chest wall invasion by Fusobacterium nucleatum.An 11-year-old female immunocompetent patient who consulted due to a two-week history of cough, night sweats, without fever or weight loss, and increased volume at the left spleen thoracic level. There was no history of chest wall trauma or travel outside the country. Two weeks before the onset of symptoms, she was treated for dental caries. Imaging studies and CT scan showed left spleen pneumonia, which invades the pleura and the chest wall. A minimal thoracotomy was performed, releasing a thick, foul-smelling liquid. The studies for common germs and tubercu losis were negative. Hematology ruled out tumor lesions. The anaerobic study reported the develo pment of Fusobacterium nucleatum. The patient was treated with penicillin followed by amoxicillin presenting good clinical and radiological responses. The dental procedure was suspected as the cause of infection.Fusobacterium nucleatum can occasionally cause remote or extra-oral in fections in immunocompetent patients, such as pneumonia with chest wall invasion, therefore it is necessary to bear it in mind.