The link between inflammation and acute coronary syndrome (ACS) remains to be sufficiently elucidated. It has been previously suggested that there is an inflammatory process associated with ACS. Pentoxifylline, a methylxanthine derivate, is known to delay the progression of atherosclerosis and reduce the risk of vascular events, especially by modulating the systemic inflammatory response. The present study is a single-blind, randomized, prospective study of pentoxifylline 400 mg three times a day (TID) added to standard therapy vs. standard therapy plus placebo in ACS patients with non-ST elevation myocardial infarction (NSTEMI). Patients with ACS were randomized to receive standard therapy plus placebo in one arm (group A; aspirin, clopidogrel or ticagrelor, statin) and in the other arm (group B) pentoxifylline 400 mg TID was added to standard therapy. The primary outcome was the rate of major adverse cardiovascular events (MACEs) at 1 year. A total of 500 patients underwent randomization (with 250 assigned to group A and 250 to group B) and were followed-up for a median of 20 months. The mean age of the patients was 62.3±10.3 years, 80.4% were male, 20.8% had diabetes, 49.4% had hypertension, and 42% were currently smoking. The statistical analysis was performed for 209 patients in group A and 210 patients in group B (after dropouts due to study drug discontinuation). A primary endpoint occurred in 12.38% (n=26) of patients in group B, as compared with 15.78% (n=33) of those in group A [relative risk (RR), 0.78; 95% confidence interval (CI), 0.486-0.1.263; P=0.40], including cardiovascular death (RR, 0.93; 95% CI, 0.48-1.80, P=0.84), non-fatal myocardial infarction (RR, 1.1; 95% CI, 0.39-3.39, P=0.78), stroke (RR, 0.99; 95% CI, 0.14-6.99, P=0.99) and coronary revascularization (RR, 0.12; 95% CI, 0.015-0.985, P=0.048). Thus, adding pentoxifylline to standard treatment in patients with ACS did not improve MACE at 1 year but had some benefit on the need for coronary revascularization.