Ankle sprains mainly caused by accidents or strenuous sport activities can often be quite painful and impair motility. If not treated immediately and correctly, sprains may lead to severe complications. The aim of the present study was to compare the efficacy and safety of topically applied ketoprofen versus orally administered ketoprofen in 20 patients with grade I ankle sprain and 34 patients with grade II sprain. The patients were divide into in two treatment groups and received either topically applied ketoprofen treatment (ketoprofen 10% spray-gel; Prontoflex; 360 mg/die) or orally administered ketoprofen treatment (ketoprofen tablets; 3x50 mg/die). Treatment duration was one week. After 3 and 7 days of treatment, reduction of spontaneous pain and pain on active movement in the Prontoflex group was significantly bigger greater in the oral treatment group, irrespective of sprain severity. Regarding secondary parameters as mobility impairment and ankle swelling topically applied ketoprofen treatment turned out to be significantly superior to orally administered ketoprofen treatment. Additionally, Prontoflex was well tolerated, whereas ketoprofen tablets caused gastrointestinal side effects in some patients. The good efficacy in pain reduction and absence of side effects in the present study distinguished the topically applied ketoprofen as a favorable treatment for patients with accidental or sport soft tissue injuries.