Introduction: Pain management after coronary artery bypass graft (CABG) surgery remains challenging.Objective: This study aimed to compare the effects of Ketorolac and Paracetamol on postoperative CABG pain relief.Method: This double-blind randomized clinical trial study was conducted in Ahvaz, Iran, from September 2018-December 2019. Two consecutive groups of 60 patients undergoing elective on-pump coronary artery bypass graft surgery.Intervention: The patients were divided into 0.5 mg/kg of ketorolac mg/dl and 10 mg/kg of Paracetamol after surgery for pain management. Primary outcomes were: visual analog pain scale (VAS) at the time point immediately after extubation (baseline) and at 6, 12, 24 and 48 h and the total dose of morphine consumption. Secondary outcomes included the hemodynamic variables, weaning time, chest tube derange, in-hospital mortality and myocardial infarction.Statistical Analysis: The data were analyzed using SPSS version 22(SPSS, Chicago, IL). The Mann-Whitney U-test was used to compare demographic data, VAS scores, vital signs, and side effects. Repeated measurements were tested within groups using Friedman's ANOVA and the Wilcoxon rank-sum test. Values were expressed as means ± standard deviations. Statistical significance was defined as a p-value