Ketoprofen (Orudis), a highly potent and safe nonsteroidal antiinflammatory drug of the propionic acid derivative group, was synthesized in France by Rhône-Poulenc chemists in 1967, 3 years after the prototype ibuprofen. Ketoprofen was introduced in 1973 in France and the United Kingdom for antiinflammatory use. Today the drug is available in about 80 countries and has recently been approved in the United States for treatment of rheumatoid arthritis and osteoarthritis. The therapeutic experience with ketoprofen is estimated to have exceeded 3 million patient-years. Double-blind trials have established its therapeutic equivalence with aspirin, indomethacin, and ibuprofen in rheumatoid arthritis and with aspirin in osteoarthritis. Ketoprofen has a short half-life, a simple metabolism, and a broad therapeutic window, and does not accumulate with multiple doses. These features contribute to a rapid onset of action, flexible dosing, and a reliable tolerance profile.