Regional anesthesia can improve postoperative analgesia and enhance the quality of recovery (QoR) after surgery. This trial evaluates the effects of ultrasound-guided bilateral superficial cervical plexus block (SCPB) on QoR in patients undergoing thyroid cancer surgery.Prospective, randomized, double-blinded, placebo-controlled trial.Operating room.Seventy-four ASA I-II female patients scheduled for thyroid cancer surgery were included to the study.Patients were randomly allocated to receive pre-operative ultrasound-guided bilateral SCPB with 10 ml of ropivacaine 0.5% or normal saline on each side.The primary endpoint was the quality of recovery, which was assessed using the 15-item quality of recovery questionnaire (QoR-15). Secondary endpoints were acute postoperative pain, time to first rescue analgesia, the number of patients requiring rescue analgesia, length of post-anesthesia care unit (PACU) stay, the incidence of postoperative nausea or vomiting (PONV) and dizziness, and patient satisfaction.The global QoR-15 score at 24 h postoperatively was significantly higher in the SCPB group (Median [IQR], 118 [115-120]) than the control group (110 [106-112]) with a median difference of 8 (95% CI: 6 to 10, P < .001). Compared with the control group, pre-operative ultrasound-guided bilateral SCPB reduced postoperative pain up to 24 h and the incidence of PONV, as well as the length of PACU stay. Additionally, the patient satisfaction scores were improved in the SCPB group (P = .024).Pre-operative ultrasound-guided bilateral SCPB with ropivacaine enhances the quality of recovery, postoperative analgesia and patient satisfaction, alleviates the incidence of PONV, and accelerates the PACU discharge following thyroid cancer surgery.