Statin therapy is indicated after ST-segment elevation myocardial infarction (STEMI) to reduce recurrent ischemic events, but approximately 6% of patients with STEMI do not receive a statin prescription at discharge. This substudy aimed to define the clinical outcomes and patient characteristics associated with statin nonprescription after STEMI. We compared clinical, angiographic, and procedural characteristics and in-hospital, 30-day, 1-year, 2-year, and 3-year outcomes in 3,512 patients discharged after STEMI with and without (6%) statin prescriptions in the harmonizing outcomes with revascularization and stents in acute myocardial infarction trial (www.clinicaltrials.gov, NCT00433966). Statin nonprescription was associated with female sex, nonwhite race, previous bypass surgery, heart failure, renal impairment, anemia, thrombocytopenia, care in the United States, lower prescription rates of antiplatelets and neurohormonal antagonists, less percutaneous coronary intervention and stents, and, in 26% of cases, angiographically normal or nonobstructed coronary arteries. At every time point of follow-up after discharge, patients with no discharge statin prescription had significantly higher rates of net adverse clinical events, major adverse cardiac events, major bleeding unrelated to bypass surgery, and death. After multivariable adjustment, absence of a discharge statin prescription independently predicted 3-year major adverse cardiac event (hazard ratio 1.54, 95% confidence interval 1.15 to 2.07, p = 0.0037) and death (hazard ratio 2.30, 95% confidence interval 1.41 to 3.77, p = 0.0009). In conclusion, within the framework of this randomized trial of patients presenting with STEMI, approximately 6% of patients were discharged without statin therapy. Absence of a discharge statin prescription after STEMI was an independent predictor of ischemic events including death.