The aim of the current study was to investigate the efficacy of greater occipital nerve (GON) block and bilateral superficial cervical plexuses (BSCP) blocks in alleviating postoperative occipital headache and posterior neck pain after thyroidectomy. This randomized prospective study consisted of 75 women undergoing total thyroidectomy. Patients were randomized into three groups: Group I (n=25): patients receiving GON, Group II (n=25): patients receiving bilateral (BSCP) blocks, and Group III (n=25): patients receiving no block. Assessment of occipital headache, posterior neck, and incision site pains was made at 12 hours and 24 hours after extubation by Visual Analogue Scale (VAS). In comparison to Group III significantly fewer patients in Groups I and II experienced occipital headache at 12 (p=0.006) and 24 hours (p=0.005) and also posterior neck pain at 24 hours (p=0.003). Mean VAS scores at 12 and 24 hours for occipital headache (p=0.003 and p=0.041) and posterior neck pain (p=0.015 and p=0.008) were significantly lower in Group I. The differences between Groups II and III were not significant except for the occipital headache at 12 hours. The efficacy of GON block is superior to BSCP blocks in alleviating postthyroidectomy occipital headache and posterior cervical pain.