We report a case of a 76-year-old man, with the occasional finding of a mediastinal cyst because of subtle chronic dysphagia associated to sore throat, belching, and dysphonia. The paraesophageal cyst in the central mediastinum was studied with computed tomography (CT) scan and transesophageal three-dimensional (3D) echocardiography with contrast echo. In order to clarify doubts about localization (intra- versus extrapericardial) of the mediastinal cystic lesion the 3D transesophageal echocardiography (TEE) confirmed the presence of a large round cystic mass located contiguous to the esophagus, the left atrium and the aortic root/pulmonary trunk (located at the front of the lesion), as well as located intrapericardial. The cystic mass showed no blood flow at color Doppler mode and at ultrasound contrast echo with SonoVue agent. Due to the paucity of symptoms and to the definite imaging information of this intrapericardial cyst of nonvascular nature, due to pericardial cyst in an extremely unusual location, surgery was not performed. At follow-up of 1 month echocardiogram and 3 month CT scan the cyst appeared unchanged in dimensions.