Purpose <p>This study assessed the efficacy of preoperative erector spinae plane block (ESPB) in reducing intraoperative opioid use and enhancing recovery in off-pump coronary artery bypass grafting (OPCABG) patients, who typically require high-dose opioids with associated postoperative risks.</p> Methods <p>A prospective, double-blind randomized controlled trial was conducted on 37 patients. Patients were randomized to receive either bilateral ESPB with 0.375% ropivacaine or a sham block with normal saline. Primary outcomes included intraoperative sufentanil consumption, while secondary outcomes encompassed hemodynamic stability, postoperative pain scores, mechanical ventilation (MV) duration, and hospital stay.</p> Results <p>The ESPB group demonstrated a significant reduction in intraoperative sufentanil consumption compared to the sham group (150.3 ± 36.1&#xa0;µg vs. 194.4 ± 38.3&#xa0;µg, <i>p</i> = 0.001). Postoperatively, ESPB patients exhibited lower pain scores at rest and during coughing within the first 6&#xa0;h post-extubation (<i>p</i> &lt; 0.001) and required less rescue analgesia (5.3% vs. 50.0%, <i>p</i> = 0.003). Additionally, ESPB shortened MV duration (5.43 ± 1.65&#xa0;h vs. 6.88 ± 1.68&#xa0;h, <i>p</i> = 0.013). No significant differences were observed in cardiac care unit or hospital stay lengths.</p> Conclusion <p>Preoperative ESPB effectively reduces intraoperative opioid requirements and provides sustained analgesia in the early postoperative period, facilitating earlier extubation. These findings support ESPB as a valuable component of multimodal analgesia in OPCABG, though further large-scale studies are needed to validate these results and optimize its application.</p> Clinical Trial Registration <p>The trial was registered with the China Clinical Trials Center (<a href="http://www.chictr.org.cn">http://www.chictr.org.cn</a>, ChiCTR2200066902) on December 21, 2022.</p>