Right heart thrombi are rare, and are often associated with poor prognosis. They are usually discovered in the setting of acute pulmonary embolism but may be found by chance during a routine echocardiography. Clinical presentations of such thrombi are variable depending on the size of the mass, obstruction of cardiac chambers and embolization to the pulmonary bed. The optimal therapeutic strategy is still a matter of debate and options include anticoagulation, fibrinolysis and surgery.We report the case of a completely asymptomatic 71-year-old patient with history of pacemaker implantation presenting for his yearly check-up. ECG found atrial fibrillation and echocardiography revealed a giant mobile right atrial thrombus (50x53mm). Anticoagulation alone resulted in complete disappearance of the thrombus after 1 month without clinical worsening. Despite the successful outcome in this patient, the best therapy for right heart thrombi remains controversial and should be individualized in each patient.