Cardiotoxicity is an uncommon adverse effect of 5-fluorouracil (5-FU). Coronary artery spasm has been postulated to be involved in the mechanism of this incident Patients may present with angina, myocardial infarction, arrhythmias and/or even sudden death. When the drug is readministered, there is a high risk of relapse. The underlying mechanisms of cardiotoxicity are not yet fully understood, although coronary vasospasm may be responsible. We report one woman receiving 5-fluorouracil therapy with typical chest pain and electrocardiographic changes consistent with acute coronary syndrome. A resolving pain and normalisation of ECG changes with nitrate therapy and normal coronary arteries indicate that this incident was about a coronary spasm caused by 5-FU.