ABSTRACT Background: Bilateral superficial cervical plexus block improves analgesia after thyroidectomy however, whether the higher technical success associated with ultrasound guidance translates into superior clinical outcomes remains unclear. Methods: In this secondary analysis of a prospective randomized trial, 60 patients who received bilateral SCPB via either the landmark technique or ultrasound guidance were evaluated for intra-operative haemodynamics, postoperative pain scores (0-120 min), and block-related complications. Results: Heart rate, systolic blood pressure, and mean arterial pressure were significantly lower in the ultrasound group at multiple intra-operative time points post-induction. Postoperative visual analogue scale scores were consistently lower in Group U. Three patients in the landmark group experienced vascular puncture, compared to none in Group U; no cases of local-anaesthetic systemic toxicity, Horner syndrome, or phrenic-nerve palsy were observed in either group. Conclusion: Ultrasound-guided bilateral SCPB is associated with improved intra-operative haemodynamic stability, reduced early postoperative pain, and a more favourable safety profile than the landmark technique in patients undergoing thyroidectomy. Keywords: Superficial cervical plexus block, Ultrasound guidance, Haemodynamic stability, Postoperative analgesia, Thyroidectomy, Complications