The objective of the study was to demonstrate a decreased incidence of postoperative nausea and vomiting (PONV) in children through the use of an antiemetic protocol. PONV was recorded in children (1.5-15 years) after inpatient surgery under general anaesthesia in a prospective, interview based survey. Group 1 consisted of children having surgery 1 month before the introduction of a formalized antiemetic protocol and group 2, 2 months after its introduction. Data were collected over a 1-month period in each group. Outcome measures of nausea, emesis, antiemetic requirement and patient satisfaction were monitored for the first 24-h postoperative period. There were 272 children enrolled: 138 in group 1 and 134 in group 2. There was a difference between the two groups for gender (P=0.03), type of surgery (P=0.017), perioperative opioid (P=0.003) and perioperative antiemetic use (P=0.024). However, multivariate analysis did not demonstrate an impact on outcome from these factors. The incidence of postoperative nausea (PON) and postoperative vomiting (POV) following the introduction of the protocol was 36% and 34%, respectively. Moderate to severe nausea was decreased after introduction of the protocol (18% versus 9%, P=0.028) but moderate to severe vomiting failed to reach significance (19% versus 11%, P=0.078). The proportion of children who had repeated nausea decreased after the introduction of the protocol (17% versus 8%, P=0.02) but repeated episodes of vomiting remained unchanged (19% versus 14%). This was attributed to a significant increase in antiemetic prescribing by protocol in group 2 (10% versus 59%, P < 0.001). Patient satisfaction was high in both groups (85% versus 90%). The introduction of a postoperative antiemetic protocol improved prescribing frequency. This resulted in a decreased incidence of moderate to severe PON and a reduction in the number of patients with repeated nausea.