A 68-year-old male patient was admitted to our hospital because of weakness, dyspnea on exertion and palpitations. Transthoracic and transesophageal echocardiograph revealed a dilated left atrium with an immobile intracavitary mass, without signs of left atrium outflow obstruction. Bronchoscopy was performed and the histopathologic review of the samples obtained was consistent with a primary lung squamous cell carcinoma.