After exposure to indomethacin, human umbilical vein endothelial cells have shown increased procoagulant activity. Thrombosis in rabbit auricular veins has been observed after injection of tenoxicam with its diluent or of the diluent alone. Human studies evaluating venous endothelium after tenoxican injection were not found in the literature. This study aimed at evaluating whether tenoxicam with 0.9% sodium chloride changes the venous endothelium of rabbits as it is observed when associated to its diluent (bidistilled water).