Aims: To compare the efficacy and safety of diclofenac-K (12.5 mg) vs paracetamol (500 mg) and placebo given in a flexible dosage regimen to treat pain resulting from extraction of impacted third molar teeth. Methods: This was a 2-day, double-blind, double- dummy, randomized, parallel-group, placebo-controlled study of diclofenac-K (12.5 mg) tablets vs paracetamol (500 mg) tablets and placebo in patients with moderate or severe pain within 8 hours of extraction of impacted third molars. Results: After the first 2-tablet dose, patients took on average 2.5 additional tablets of diclofenac-K or 2.4 tablets of paracetamol, almost all as 1- tablet doses. Most placebo patients discontinued by taking rescue medication (ibuprofen 200 mg) on the first day. Pain relief after the initial dose of diclofenac-K (2
12.5 mg) was superior to placebo (P  .01 for all efficacy outcomes) and comparable to paracetamol (2
500 mg). About 30% of patients in each active treatment group took rescue medication during the study, compared to 78% on placebo. About 70% in each active treatment group considered the overall pain relief to be “some,” “a lot,” or “complete” compared to only 15% on placebo. The incidence of adverse events in each active treatment group was low and comparable between the treatments. Conclusion: An initial double-dose of diclofenac-K (2
12.5 mg) or paracetamol (2
500 mg) adequately relieved the most intense postoperative pain, and the flexible multiple dose regimen (1 or 2 tablets) maintained adequate pain relief thereafter. Most patients needed only 1-tablet doses following the initial 2-tablet dose. J OROFAC PAIN 2003;17:237–244.