Backgrounds: We sought to define the pattern, the clinical outcome and the risk predictors of stent strut fracture (SSF) after drug-eluting stent (DES) implantation. Methods. We gathered SSF cases in 13 centers in Korea. SSF was diagnosed in coronary angiograms showing definite interruption of the linear or curvilinear connection of the stent struts. In addition, SSF was identified in intravascular ultrasounds (IVUSs) showing more than one image slice with a loss of stent struts. Furthermore, we classified the SSFs into three patterns (disruption, avulsion, and displacement) according to the interruption site and absence or presence of displacement. Results. Thirty-seven SSFs(2 disruption, 7 avulsion, 28 displacement) occurred in 35 lesions in 35 patients. All fractured stents were sirolimus-eluting stents (SESs). The average length of stent used was 49 mm, overlapping stenting was performed in 19 lesions (54%), and the average maximal angulation in the initial coronary angiography was 67째. All of these factors appear to be risk predictors of SSF. Twenty-four fractures (65%) were associated with focal in stent restenosis and 11 fractures (30%) with target lesion revascularization. No acute coronary syndrome developed. Conclusions. SSF after DES implantation is not rare, especially after SES implantation. Long stenting, overlapping stenting and severe angulation are risk predictors of SSF. However, because it has relatively good clinical outcome, SSF is not serious enough to prevent DES implantation