Objectives: The present study was conducted to compare the effect of gargling normal saline mixed with honey and cold normal saline on postoperative pain relief in children undergoing tonsillectomy or adenotonsillectomy during 2018. Methods: This clinical trial was performed on 105 children aged 5-14 years. The participants were randomly allocated to three 35-member groups, viz. normal saline mixed with honey, cold normal saline, and the control. The patients underwent general anesthesia and then were operated by a single surgeon. Gargle was administered in the first and second groups every six hours up to 48 hours following the surgery. There was no intervention in the control group. The pain was recorded by the Wong-Baker FACES Pain Rating Scale (WBS) at the recovery time and 6, 12, 18, 24, 36, 48 hours and 7 days after the surgery. Data were analyzed using repeated measures ANOVA. Results: Among the participants, 47 subjects (44.8%) were males and the rest were females, with a mean age of 8.6 ± 2.5 years. The three groups were similar in terms of sex, weight, duration of surgery, and bleeding during surgery. The pain at the site of surgery during both resting and swallowing was different at 6, 12, 18, 24, 36, 48 hours, and 7 days following the surgery (P < 0.001). Conclusions: Gargling cold normal saline and normal saline mixed with honey led to reduced pain after tonsillectomy or adenotonsillectomy; however, the latter had a higher effect on the postoperative pain relief.