Introduction: Postoperative analgesia in elderly patients is still a thorny problem. Ultrasoundguided oblique subcostal transverse abdominis plane block (TAPB) has been demonstrated to provide postoperative analgesia after abdominal surgeries. However, recent studies have suggested that an alternative method, erector spinae plane block (ESPB), might also be effective. In this study, we compared the postoperative analgesic effects of ESPB and TAPB in elderly patients who had undergone laparoscopic colorectal surgery. Methods: Sixty-two elderly patients (C 65 years old) scheduled for elective laparoscopic colorectal surgery with general anesthesia were randomly allocated to two equally sized groups: ESPB group and TAPB group. The ESPB group had a bilateral erector spinae plane block, and the TAPB group had a bilateral oblique subcostal transverse abdominis plane block. The primary outcome was visual analogue scale (VAS) pain score during the first 24 postoperative hours at resting and active states. The secondary outcomes were postoperative consumption of sufentanil, satisfaction score, the number of patients who required antiemetics, incidence of block-related complications, and other side events. Results: There were no demographic differences between two groups. Compared to the TAPB group, the ESPB group had lower VAS pain scores and sufentanil consumption during the first 24 postoperative hours. Additionally, ESPB reduced the occurrence of postoperative nausea and vomiting. Furthermore, the satisfaction score was higher in the ESPB group. No other complications were reported between the two groups. Conclusions: Compared with oblique subcostal TAPB, ESPB more effectively reduced postoperative pain and opioid consumption. Thus, ESPB is suitable for postoperative analgesia in elderly patients who have undergone laparoscopic colorectal surgery.