Multiple studies have confirmed that erector spinae block is effective in thoracic and breast surgeries. However, studies which investigate the efficacy of this block in cardiac surgery are scarce. This study aimed to compare continuous erector spinae block with multimodal intravenous analgesia in coronary bypass surgery. Methods: Forty patients undergoing coronary bypass surgery were divided into either group A (IV) (n = 20) who received multimodal intravenous analgesia or group B (ES) (n = 20) who had continuous erector spinae block. We compared the two groups regarding Visual Analog Scale (VAS) till 48 h after extubation, total perioperative opioid consumption, post-extubation peak inspiratory flow, duration of mechanical ventilation and ICU stay. Results: Group B showed a significantly lower VAS score than group A. intraoperative fentanyl was significantly less in group B (403.75 ± 44.63) versus (685 ± 99.47) in group A, p = 0.00. Postoperative morphine doses were 50% less in group B; (15.9 ± 2.63) versus (32.3 ± 5.04) in group A, p = 0.00. Peak inspiratory flow was significantly higher in group B after extubation. Duration of ventilation was shorter in group B (4.96 ± 0.71 h) versus (6.08 ± 0.69) in group A, p = 0.00. In addition, ICU stay was also shorter in group B (35.52 ± 3.87 h) versus (47.06 ± 5.08 h) in group A, p = 0.00. No clinically significant adverse effects were recorded. Conclusion: Ultrasound-guided bilateral continuous erector spinae block produced safe and effective analgesia for 48 h after extubation following coronary bypass surgery. It also reduced perioperative opioid consumption and allowed early tracheal extubation without major adverse effects.