The effects of etoricoxib on blood coagulation parameters were evaluated, along with acetylsalicylic acid, in male Wistar rats. Blood samples were collected at the end of the first, second, third and fourth weeks of the administration period and the plasma concentrations of etoricoxib determined by liquid chromatography-tandem mass spectrometry; the samples were also used for the analysis of the hematological parameters. There were no significant changes in the platelet count and fibrinogen levels, and a decrease by 1.9% of the prothrombin time was detected at the third week. The activated partial thromboplastin time assay showed a nonsignificant shortening. The antiactivated factor X and antiactivated factor II activities showed reductions lower than 2.8 and 1.3%, respectively. These findings and the comparison with acetylsalicylic acid can be helpful to support the benefit-to-risk profile, contributing to the safe therapeutic use.