Frequently, decisions about analgesic treatment of postoperative pain in children are based on judgments made by nurses. Several studies from North America indicate that nurses underestimate the amount of pain experienced by children. Additional investigations are required to evaluate the extent to which this problem affects children in other countries and societies that have various health-care systems. The purpose of this study was to examine the relationship between children's ratings of their pain and the nurses' ratings of the children's pain in a Danish hospital. The issue was examined by comparing the pain ratings of 100 children 3-15 years of age following tonsillectomy. The ratings were obtained by using the poker chip tool and a 10-cm visual analogue scale. In general, nurses underestimated the children's pain. The differences were most pronounced after analgesics (P < 0.001). The nurses tended to overestimate the effect of analgesics. Although the correlations between the children's and the nurses' pain scores were statistically significant (r = 0.35-0.43, P < 0.001), the findings indicate that the nurses are not good at interpreting the patients' pain. These results from Danish children and nurses are similar to studies in other populations.