Nonsteroidal anti-inflammatory drugs (NSAIDs) are the most commonly used drugs to reduce pain and inflammation (1). Celecoxib (CXB), a selective cyclo-oxygenase-2 (COX-2) inhibitor, has been recommended orally for the treatment of arthritis and osteoarthritis (2). Long-term oral administration of CXB causes serious gastrointestinal side effects (2). Furthermore, poor aqueous solubility of CXB limits its formulation as topical dosage forms. Therefore, an improved CXB formulation with a high degree of permeation could be useful in the treatment of locally inflamed skin and inflammatory and painful states of the body, like bones, ligaments, etc. Topical vehicle systems can modify drug permeation through the skin but many dermal vehicles contain chemical enhancers and solvents to achieve these goals (3). The use of these chemical enhancers may be harmful especially in chronic applications, since many of them are usually irritants. It is therefore desirable to develop a topical vehicle system, that does not necessitate the The aim of the present study was to investigate the potential of nanoemulsion formulations for transdermal delivery of celecoxib (CXB). The in vitro skin permeation profile of optimized formulations was compared with CXB gel and nanoemulsion gel. Significant increase in the steady state flux (J ss ), permeability coefficient (K p ) and enhancement ratio (E r ) was observed in nanoemulsion formulations T1 and T2 (p < 0.05). The highest value of these permeability parameters was obtained in formulation T2, which consisted of 2% (m/m) of CXB, 10% (m/m) of oil phase (Sefsol 218 and Triacetin), 50% (m/m) of surfactant mixture (Tween-80 and Transcutol-P) and 40% (m/m) water. The anti-inflammatory effects of formulation T2 showed a significant increase (p < 0.05) in inhibition after 24 h compared to CXB gel and nanoemulsion gel on carrageenan-induced paw edema in rats. These results suggested that nanoemulsions are potential vehicles for improved transdermal delivery of CXB.