Worldwide experience with the conventional formulation of etodolac (300 mg b.i.d.) was reviewed in 12 randomized, double-blind, parallel-group studies in patients with osteoarthritis (OA) of the hip or knee. The studies were conducted in 13 countries at 59 sites, and 1289 patients were enrolled. The results of 9 comparative and 3 placebo-controlled clinical studies were examined to compare the efficacy and safety of etodolac versus piroxicam, naproxen, indomethacin, indomethacin sustained-release (SR), and diclofenac SR. Efficacy assessments were made at pretreatment screening, baseline, and every 2 weeks thereafter during treatment until study completion up to 4, 6, or 8 weeks. The primary efficacy assessments were the patient's and physician's global evaluations, pain intensity and night pain, or joint tenderness and walking pain. Safety was assessed with reference to study events, reports of laboratory results, and vital signs measurements. Patients in all active treatment groups showed prompt response to therapy. According to the physicians' global evaluation, at least 64% of all etodolac-treated patients and 62% of all active-reference preparation-treated patients had improved by the end of the study. Similar results were seen in the patients' global evaluation. All of the study drugs were well tolerated. Eight (8%) percent of the etodolac-treated patients withdrew because of study events. The proportions of patients treated with active reference preparations and placebos who withdrew because of study events ranged from 3% to 18%. The results reported in this review indicate that etodolac (300 mg b.i.d.) is effective and safe in the treatment of the signs and symptoms of OA and that it compares favorably with piroxicam, naproxen, indomethacin, indomethacin SR, and diclofenac SR.