We report a case of specific myocardiotoxicity due to 5 F.U. not previously described in man. A 41-year-old man was admitted to the ICU for heart and renal failure, appearing 24 h after 5 days treatment with 5 F.U. and cis-platinum. Dopamine was necessary to maintain blood pressure. Two-D echocardiography and a right heart catheterisation confirmed the alteration of myocardial contractility. After 2 weeks a complete cardiac recovery occurred.