Abstract : Modified radical mastectomy (MRM) is generally carried out under general anesthesia. Regional anesthesia provides hemodynamic stability and fewer post-surgical complications. This study evaluates the effectiveness of pectoral block I and II anesthesia compared to thoracic epidural anesthesia in MRM. This is an experimental research using a permuted block randomization sampling. This study involved 26 patients aged 18-70 years who underwent breast surgery with the laryngeal mask airway. Group A of 13 people received pectoral block I and II techniques, while the group B of 13 people received thoracic epidural technique. The mean arterial pressure and heart rate in both groups did not show any significant difference during the course of the surgery. Resting NRS is lower in group B compared to group A at 2, 4, 6, and 24 hours postoperatively. The classification of postoperative NRS in both groups referred to the mild pain category. The thoracic epidural technique is more effective in reducing postoperative pain scores compared to pecs block. Both techniques provide similar effectiveness in maintaining hemodynamic stability during surgery