We assessed the prevalence, predictors, and in-hospital and long-term outcomes of conservative medical management for patients with non-ST-segment elevation acute coronary syndrome (NSTEACS) compared with percutaneous coronary intervention (PCI) and coronary artery bypass graft surgery (CABG). This prospective study conducted from October 2008 to June 2009 in 65 hospitals from 6 Arabian Gulf countries included 30-day and 1-year mortality follow-up for 3661 patients. Compared with conservative management group (2859 patients; 78.1%), the PCI group (638; 17.4%) had significantly better unadjusted and adjusted in-hospital (odds ratio [OR]: 0.40, 95% confidence interval [CI]: 0.17-0.97), 30-day (OR: 0.44, 95% CI: 0.24-0.76) and 1-year (OR: 0.58, 95% CI: 0.40-0.87) mortality rates. Comparison with the CABG group (164; 4.5%) yielded similar results with inclusion of patients scheduled for CABG after hospital discharge. Independent predictors of conservative medical management were mainly country of residence and history of prior CABG.