At therapeutic concentrations, parecoxib selectively inhibits the cyclo-oxygenase-2 enzyme. We investigated the impact of a single preoperative dose of parecoxib on pain relief following minor gynaecological surgery. Ninety women undergoing uterine dilatation and curettage, with or without hysteroscopy, were randomised to receive either 40 mg of parecoxib intravenously or a saline placebo prior to induction of standardised general anaesthesia. Exclusion criteria included a preoperative history of renal dysfunction or hypertension and the preoperative use of anti-inflammatory or opioid medication. The primary endpoint was the pain score during recovery. There was no difference in global pain scores or area under the curve for pain scores in the recovery area. Pain scores with coughing one hour after surgery were low in both groups but significantly lower after parecoxib (median 2 [interquartile range 0 to 4] parecoxib group vs. 2 [interquartile range 0 to 6] placebo group, P = 0.037). The 24 hour Quality of Recovery score did not differ significantly between groups but the parecoxib group was less likely to experience headache at 24 hours postoperatively (12 vs. 38%, P = 0.007) and reported complete satisfaction more frequently (78 vs. 57%, P = 0.042). The preoperative administration of parecoxib was associated with a significant but small decrease in dynamic pain scores one hour postoperatively. Women who received preoperative parecoxib had a lower incidence of postoperative headache and higher satisfaction.