Background: Thyroidectomy is the most common endocrine surgical procedure, and many challenges are encountered during the preoperative, intraoperative, and postoperative periods. After thyroidectomy, bilateral superficial cervical block is the most successful option reducing postoperative pain, analgesic needs and post-operative complications such as vomiting. Objective: Our study aimed to evaluate the analgesic effect, onset time of sensory block, duration time, postoperative visual analogue score (VAS) and complications of adding dexmedetomidine versus dexamethasone to levobupivacaine for cervical plexus block. Patients and Methods: A prospective-randomized clinical trial study that was conducted at Sohag University between April 2018 and March 2020. The study included fifty patients with (ASA) Class I or II, aged 30 to 60 years were scheduled for euthyroid surgeries (including thyroid adenoma, Hashimoto's goiter, and nodosity thyroiditis) Results: The addition of dexmedetomidine to levobupivacaine (group D) shortened the sensory block onset time compared to dexamethasone added to the levobupivacaine group (group S) (p < 0.05). The duration of analgesia of cervical plexus block in group (D) was significantly longer than that in group (S) (232.34 versus 303.55 min; p < 0.05). HR level in group (D) was significantly lower than that in group (S) (p < 0.05). Conclusion: The addition of 1 μg kg−1 dexmedetomidine to levobupivacaine for cervical plexus block (BSCPB) shortened the sensory block onset time and extended the duration of analgesia and increased the quality of analgesia more superior than the addition of dexamethasone.