To assess the sore throat pain model in children as an assay for systemic analgesic agents in children under double-blind, placebo-controlled conditions, we conducted a single-dose parallel study that compared 10 mg/kg ibuprofen (n = 39), a new analgesic agent for children, and 15 mg/kg acetaminophen (n = 38), an approved analgesic for children, to placebo (n = 39) in children from 2 to 12 years of age with acute sore throat. At 1/2, 1, 2, 3, 4, 5, and 6 hours (2 hours in the pediatrician's office followed by 4 hours at home), children assessed pain intensity with a pain thermometer and pain relief with a smiley-face scale. The parent and pediatrician assessed pain intensity and change in pain; the parent also provided an overall evaluation at 6 hours. The children rated ibuprofen and acetaminophen as significantly effective compared with placebo (p < 0.05) on both scales at most posttreatment time points and overall. The parent and pediatrician also rated both active medications as significantly different from placebo on both of their scales (p < 0.05) at several time points and overall. On the parent's overall evaluation, ibuprofen was rated as effective compared with placebo (p < 0.05). Both active agents significantly (p < 0.05) reduced oral temperature in children with baseline temperatures > 99 degrees F. No treatment-related adverse effects were observed. We conclude that the sore throat pain model is a sensitive assay for identification of the activity of oral analgesic drugs in children and that ibuprofen is an effective analgesic in children.