A review of the literature shows a constant need to improve the quality of postoperative pain management. The objective of this study was to decrease the intensity and variation of postoperative pain by developing a nurse-based pain service on the ward. An acute pain nurse was appointed and an educational programme with detailed algorithms was started. Regular pain intensity measurements were implemented. Postoperative pain intensity, treatments and side-effects were assessed both before and after the introduction of the new system in 400 patients divided into two consecutive groups of equal size. The number of patients with inadequately treated pain (actual pain > 3/10) dropped by 64% after major gynaecological surgery (25 vs 9%, 95% CI for differences 7-24%; p 3/10) on the first postoperative day was more frequent on the ward before than after the reform (47 vs. 21%; 95% CI for differences 15-35%; p 0.05). The intensity and variation of postoperative pain on the ward decreased by developing a nurse-based pain service with an acute pain nurse, an educational programme and regular pain intensity measurements.