In the Evaluation of Platelet IIb/IIIa Inhibition in Stenting Trial (EPISTENT), abciximab reduced ischemic complications of stent implantation at 30 days and 6 months. The responsible mechanisms remain unclear. We sought to determine if abciximab decreases ischemic complications by decreasing the incidence of angiographic complications during coronary stenting. In EPISTENT, patients were randomized to stenting with abciximab (abciximab group), stenting with placebo (placebo group), or balloon angioplasty with abciximab. Angiographic complications (including major or minor dissection, distal embolization, thrombus postprocedure, side branch or other vessel occlusion, residual stenosis >50%, transient coronary occlusion, and Thrombolysis In Myocardial Infarction final flow <3) were recorded prospectively. Creatine kinase (CK)-MB enzyme levels after intervention were measured at 6-hour intervals. We analyzed angiographic complications and CK-MB elevations in the abciximab group (n = 784) and the placebo group (n = 803). Angiographic complications were 29% less frequent in the abciximab group compared with the placebo group (17.0% vs 23.8%; p = 0.001). In patients with angiographic complications, there was a nonsignificant reduction in the incidence of CK-MB elevation >3 times normal with abciximab therapy (19.7% vs 24.5% in placebo group; p = 0.314). Abciximab (compared with placebo) significantly reduced the incidence of CK-MB elevation >3 times normal in those without any angiographic complications (6.5% vs 10.7%; p = 0.007). In summary, abciximab (compared with placebo) significantly reduced angiographic complications during coronary stenting. Abciximab also prevented CK-MB elevations in patients without angiographic complications.