Introduction. Gastric ulcer is a multifactorial disease, which its pathophysioligy has not been clear yet. The aim of this study was to obtain the prophylactic effects of EDTA on Aspirin induced gastric mucosal lesions. Methods. In fasted male rats the effect of a single oral dose of the EDTA was evaluated in the following test systems: combination of 1 ml EDTA 1.5% + 300 mg/kg aspirin and 1 ml EDTA 1.5%, 2.5%, 5% and 7.5% 30 minutes before 300 mg/kg aspirin. Then the gastric mucosal lesions were assessed microscopically and marcroscopically. Results. EDTA at different doses reduced macroscopic and microscpic gastric mucosal lesion induced by aspirin. Discussion. Combination therapy of EDTA and aspirin has distinct advantages regard to both low gastrointestinal toxicity and restored therapeutic activity.