Several predominantly North American studies indicate that postoperative pain experienced by children is underestimated by the nurses, who are in charge of the analgesic treatment of the children's pain. The purpose of this investigation was to examine, in Danish children, the relationship between the children's ratings of their pain and the nurses' ratings of the children's pain. The issue was examined by comparing the pain ratings of 100 children three to 15 years of age following tonsillectomy. The ratings were obtained by using the Poker Chip Tool and a 10-cm Visual analogue scale. The differences between the children's and the nurses' pain ratings were most pronounced after administration of analgesics (p < 0.001). After analgesics, the children's mean pain score was 17% lower than before analgesics, while the nurses' mean pain scores of the children's pain were 53-58% lower than before analgesics. Consistent with results from foreign studies, this Danish study found that, in general, the nurses underestimated the children's pain. The nurses tended to overestimate the effect of analgesics and tended to modify their pain ratings according to the children's level of activity.