Paracetamol and non-steroidal anti-inflammatory drugs are often administered for postoperative analgesia. Dilatation and curettage, with or without hysteroscopy, is a common day-stay procedure that is associated with pain that is partly mediated by prostaglandins. This study aimed to investigate the analgesic efficacy of adjunctive paracetamol and parecoxib in this setting. A randomised, blinded, placebo-controlled, single-centre trial was conducted among 240 women undergoing dilatation and curettage. Patients were randomised intraoperatively into one of four groups, to receive either intravenous paracetamol 2 g, intravenous parecoxib 40 mg, both in combination, or placebos, post-induction and with intravenous fentanyl. The primary endpoints were pain score one hour postoperatively and the Overall Benefit of Analgesia Score. There were no statistically significant differences in primary outcomes across groups. The area under the curve for pain scores to two hours postoperatively was significantly lower in the group receiving paracetamol (P=0.018) and the need for rescue analgesia with tramadol was less in the combination group (P=0.02). There were no significant differences in patient satisfaction or recovery. We conclude that paracetamol or parecoxib does not produce a clinically important reduction in pain in this setting. Women having uterine curettage and receiving intravenous fentanyl do not appear to benefit from administration of these non-opioid analgesics.