Background Hypertension is a well known risk factor for atherosclerosis. However, data on the prognostic impact of hypertension in patients with ST elevation myocardial infarction (STEMI) are inconsistent and mainly related to studies performed in the thrombolytic era, with very few data in patients undergoing primary angioplasty. Therefore, the aim of the current study was to evaluate the impact hypertension on clinical outcome in STEMI patients undergoing primary PCI with BMS or DES. Methods Our population is represented by 6298 STEMI patients undergoing primary angioplasty included in the DESERT database from 11 randomized trials comparing DES vs BMS for STEMI. Results Hypertension was observed in 2764 patients (43.9%), and associated with ageing (p < 0.0001), female gender (p < 0.001), diabetes (p < 0.0001), hypercholesterolemia (p < 0.0001), previous MI (p = 0.002), previous revascularization (p = 0.002), longer time-to-treatment (p < 0.001), preprocedural TIMI 3 flow, and with a lower prevalence of smoking (41% vs 53.9%, p < 0.001) and anterior MI (42% vs 45.9%, p = 0.002). Hypertension was associated with impaired postprocedural TIMI 0-2 flow (Adjusted OR [95% CI] = 1.22 [1.01-1.47], p = 0.034). At a follow-up of 1201 ± 440 days, hypertension was associated with higher mortality (adjusted HR [95% CI] = 1.24 [1.01-1.54], p = 0.048), reinfarction (adjusted HR [95% CI] = 1.31 [1.03-1.66], p = 0.027), stent thrombosis (adjusted HR [95% CI] = 1.29 [0.98-1.71], p = 0.068) and TVR (adjusted HR [95% CI] = 1.22 [1.04-1.44], p = 0.013). Conclusions This study showed that among STEMI patients undergoing primary angioplasty with DES or BMS, hypertension is independently associated with impaired epicardial reperfusion, mortality, reinfarction and TVR, and a trend in higher ST.