Hypertension is well established as a risk factor for the development of atherosclerosis. Data on the impact of hypertension in patients with ST elevation myocardial infarction are so far inconsistent, and are mainly related to studies performed in the thrombolytic era. We assessed the impact of hypertension over the short and long term in 560 patients with ST elevation myocardial infarction (STEMI) and without previously known diabetes, all of whom were submitted to mechanical revascularization and consecutively admitted to our Intensive Cardiac Care Unit. Hypertensive patients were older (p < 0.001), more frequently male (0.005), and they showed a reduced eGFR (p < 0.001). Smoking was more frequent in nonhypertensive patients (p < 0.001), while the incidence of three-vessel coronary artery disease was higher in hypertensive patients (p = 0.003). No difference in the in-hospital mortality rates for the two subgroups was detected. At follow-up (median 32.5 months, 25th–75th percentile 16.9–47.3 months), Kaplan–Meier survival analysis detected no differences in mortality between hypertensive and nonhypertensive patients (log rank χ ² 0.38, p = 0.538). According to our data, obtained from a large series of consecutive STEMI patients without previously known diabetes, all of whom were submitted to primary PCI, a history of hypertension does not affect mortality over either the short or the long term. Moreover, hypertensive patients showed an altered glucose response to stress, as indicated by higher admission glucose values, poorer in-hospital glucose control, and a higher incidence of acute insulin resistance (as indicated by the HOMA index). Hypertensive patients therefore appear to warrant careful metabolic management during their hospital courses.