Since its introduction as a new anti-platelet agent a decade ago, clopidogrel has been shown to be a useful drug in the treatment of non-ST elevation acute coronary syndromes. Its use in such conditions has been advocated by national UK, European and international guidelines issued by a number of professional regulatory authorities. However, in the past few years, new evidence has emerged from a number of clinical trials supporting the expansion of clopidogrel use to include ST elevation myocardial infarction and patients undergoing both urgent and elective percutaneous coronary interventional procedures in the form of an initial loading dose followed by a daily maintenance dose, usually for a period of 12 months. This review paper aims to highlight areas in clinical practice where clopidogrel use does not follow the agreed guidelines. It also compares the published UK, European and international guidelines with the up-to-date evidence that recently became available from clinical trials. The paper also outlines some suggested recommendations to be considered when issuing any new clopidogrel-related guidance documents.