The generalisation of the use of transthoracic echocardiography in the investigation of pulmonary embolism leads to the diagnosis of mobile right heart thrombus in about 5% of cases. A review of the literature shows that this association is mainly observed in clinically severe pulmonary embolism. The presence of a mobile right heart thrombus is associated with a poor prognosis and emergency treatment is based on thrombolytic therapy or surgical embolectomy. In minimal or infraclinical pulmonary embolism, the finding of a mobile right heart thrombus is rare and there is no consensus about its treatment. The authors report the case of a 61 year old man admitted to hospital for bilateral deep vein thrombosis with no symptoms of pulmonary embolism in whom investigations revealed a mobile right heart thrombus with minimal pulmonary embolism. The outcome was favourable with progressive resolution of the right heart thrombus with oral anticoagulation after three weeks of heparin therapy.