The purpose of this single-dose, randomized, placebo-controlled, and double-blind study was to evaluate the analgesic dose-response relationship of 50-mg, 100-mg, 200-mg, and 400-mg doses of ibuprofen after third molar surgery. Patients were instructed to take a single dose of either placebo or 50 mg, 100 mg, 200 mg, or 400 mg of ibuprofen when the postoperative pain was moderate to severe. Acetaminophen 500 mg was used as a rescue medication. Pain intensity, pain relief, and any possible adverse events were recorded on self-administered questionnaires hourly for 6 hours after intake of study medication. If rescue medication was taken, the time of intake was registered. A total of 304 patients entered the study, and 258 complied with the protocol. A positive analgesic dose-response relationship of 50-mg, 100-mg, 200-mg, and 400-mg doses of ibuprofen was observed when evaluated by pain intensity difference, sum of pain intensity difference, pain relief, total pain relief, and survival distribution of patients not taking rescue medication. Although significant pain relief was seen after a dose of 50 mg ibuprofen, ibuprofen 400 mg provided maximum pain relief and the longest duration of analgesic effect. Mild transient adverse events were reported by 6.8% of the patients. However, there was no significant difference in frequency between the placebo and 50 mg, 100 mg, 200 mg, and 400 mg ibuprofen dose groups.