The aim of the present study was to evaluate the additional prognostic effect of ST-depression resolution in 610 patients who had ST-elevation myocardial infarction and underwent successful primary angioplasty (postprocedural Thrombolysis In Myocardial Infarction 3 flow and complete resolution of ST-segment elevation). Incomplete resolution of ST-segment depression (<70%) was observed in 50 patients (8.2%). These patients were older, had a higher Killip's class at presentation, had larger infarcts, and had an increased 1-year mortality (10% vs 2%, p = 0.0004). At multivariate analysis, incomplete resolution of ST-segment depression was an independent predictor of 1-year mortality (p = 0.028).