Using data from the 2nd Gulf Registry of Acute Coronary Events (Gulf RACE-2) in 2008-09 we investigated the in-hospital complications and 1-year outcome of acute coronary syndrome (ACS) in patients with systemic hypertension from 6 Gulf countries. Of 7847 consecutive patients admitted with ACS, 3746 (47.7%) had hypertension. Hypertension was more prevalent in women, in Arabs than non-Arabs and in older age groups. Patients with hypertension were more likely than those without hypertension to present with dyspnoea and advanced Killip class. Among hypertensive patients, the mortality rate was higher only among those admitted with ST-elevation myocardial infarction. After adjustment for baseline variables, hypertension was an independent predictive factor for heart failure (OR = 1.31) and stroke (OR = 2.47). here were no significant differences in mortality in hypertensive ACS patients when stratified by sex, age or ethnicity.