This study was designed to introduce and evaluate a research-based intervention to improve night-time pain management. It involved the provision of patient information and the introduction of structured night-time pain assessment. The implementation of the intervention was undertaken by local opinion leader. The study involved 417 patients from two matched orthopaedic wards in a before and after trial with comparison group. Outcomes of night-time pain control were elicited from ward documentation and patients by structured interviews on the second postoperative morning. These incorporated retrospective pain assessments, analgesic provision and nursing comfort measures provided the previous night. The intervention was associated with statistically significant reductions in both average and worst overnight pain scores. The frequency of night-time pain assessment by nursing staff increased significantly, although patients did not volunteer reports of pain more frequently and analgesics and other comfort measures were no more frequent. The intervention required an investment in educational support but no additional resources were needed for the successful reduction in pain scores.