OBJECTIVES: Children undergoing surgery often experience anxiety, exhibit negative behaviors and suffer postoperative pain. Previous studies showed inconsistent findings in the effects of therapeutic play intervention on children’s perioperative anxiety, negative behaviors and postoperative pain. This study aimed to examine the effectiveness of a therapeutic play intervention on perioperative anxiety, negative emotional manifestation and postoperative pain in children undergoing inpatient elective surgery. METHODS: A randomized controlled trial with two-group pre- and post-tests study design was conducted. A total of 106 eligible children (6-14 years old) were recruited and randomly allocated to either a control group (receiving routine care) (n = 53) or an experimental group (receiving one-hour therapeutic play intervention in addition to routine care) (n = 53). Outcome measures included children’s anxiety, emotional manifestation and postoperative pain which were conducted at baseline (3-7 days before the operation), on the day of surgery, and around 24 hours after surgery.  Repeated measures ANCOVA and univariate analysis of covariance were used to analyse the data.  RESULTS: : Children in the experimental group demonstrated no superior result in perioperative anxiety (p > 0.05), but indicated significantly fewer negative emotional manifestations (p < 0.01) and less postoperative pain (p < 0.01) as compared with those in the control group. CONCLUSIONS: The therapeutic play intervention is superior to usual care in reducing negative behaviors and postoperative pain in children undergoing inpatient elective surgery. These findings suggest the need of providing the therapeutic play intervention for school-aged children who are undergoing inpatient elective surgery.