SummaryThe authors report a case of primary pericardial mesothelioma.A 40 year-old man was admitted for exertionnal dyspnea and abdominal disconfort.The clinical picture and the chest X-ray were suggestive for a pericardial tamponnade. The echo-cardiographic examination revealed a«swinging heart».Despite numerous investigations, including analysis of the pericardial fluid, the diagnosis has only can be made by the port-mortem examination.The authors pointed out the difficulties of diagnosis and the need to perform rapidly a thoracotomy in front of a relapsing hemorragic effusion.The recent world literature is briefly reviewed.