Two cases of 5-Fluorouracil (5FU) cardiotoxicity, chest pain with changes in ECG the former, and myocardial infarction the latter, are described. Review of literature shows the existence of 49 cases of cardiotoxicity due to 5FU (38 angina = 77.5% 8 myocardial infarction = 16.3%). This complication seems due to a "coronary toxicity" whose onset is very precocious and not dose-dependent. Since 5FU therapy could result very dangerous when cardiotoxicity occurs, it is strictly advisable to withdraw further administration of the drug. As a matter of fact 18 patients out of 21 who again were treated with 5FU, had more serious complications which resulted in 3 myocardial infarctions (2 deaths).