The aim of this study was to compare postoperative pain after robotic thyroidectomy with that after conventional open thyroidectomy. We analyzed 123 patients who underwent robotic thyroidectomy and 170 patients who underwent conventional open thyroidectomy. Postoperative pain was evaluated on a visual analogue scale rating of 0 to 10, 1 day to 1 month after surgery. Mean pain visual analogue scale scores for the robotic and open groups were 3.33 and 3.57 (P=0.476) on day 1, 2.29 and 2.58 (P=0.285) on day 3, 2.19 and 1.74 (P=0.057) after 1 week, and 0.98 and 1.01 (P=0.843) after 1 month, respectively. There was no difference between the 2 groups in the doses of parenteral analgesic medication administered (robotic vs. open, mean 174 vs. 194 mg, P=0.189). In conclusion, postoperative pain and the dose of analgesic medication in both groups are similar.