Drug-eluting stents (DES), which locally elute antiproliferative drugs, can dramatically inhibit neointimal growth. However, several pathological studies have indicated that DES may delay healing after vascular injury, and DES implantation may be theoretically associated with a risk of coronary artery aneurysm formation. Coronary aneurysms have been reported from 3 days to up to 4 years after DES implantation procedures, with varying clinical presentations. The incidence of coronary artery aneurysms after DES implantation is low within the first 9 months, with a reported incidence of 0.2% to 2.3%, a rate similar to that reported after bare-metal stent (BMS) implantation (0.3% to 3.9%) in the DES versus BMS randomized trials. However, the true incidence of coronary aneurysms in an unselected patient population is still largely unknown. This article reviews the published literature on coronary artery aneurysms specifically relating to DES.