The use of allopurinol has shown promising outcomes in reducing oxidative processes responsible for atherogenic-related cardiovascular events. The current study aims to assess the effects of high-dose allopurinol on the post-revascularization coronary blood flow and inflammatory biomarkers in patients with non-ST segment elevated myocardial infarction (NSTEMI). Eighty NSTEMI patients were randomly divided into two groups: the intervention group (n=40), medicated with a high loading dose of 600 mg allopurinol before the coronary angiography, and the control group (n=40), treated with a placebo. The highly sensitive C-reactive protein (hs-CRP) was measured at baseline and within 24 hours after the cardiac interventions and compared between the case and control groups. Post percutaneous coronary intervention (PCI) Thrombolysis in Myocardial Infarction (TIMI) flow grading was also evaluated as a revascularization endpoint. The two groups of the study were similar in terms of demographic, clinical, laboratory, and angiographic characteristics (P-value>0.050). The assessed TIMI flow was similar between the cases and the controls both prior to (P-value=0.141) and after (P-value=0.395) the coronary angioplasty. The hs-CRP (P-value=0.016) was significantly higher in the control group. Post-angiographic assessment of hs-CRP revealed an insignificant difference between the groups (P-value=0.104). In conclusion, premedication with a high dose of allopurinol in NSTEMI patients did not affect the inflammatory biomarker or the revascularization endpoint.