Background: There is a great interest towards the medicinal herbs as a new line of treatment with less side effects. Objective: Evaluation and standardization of the protective effect of Ocimum basilicum extract which is used as traditional medicine against ethanol-induced gastric mucosal damage. Material and Methods: Fifty adult male albino rats of local strain weighing between 150 and 185 grams were used for this study. The rats were divided into four groups, control, ethanol-treated, Ocimum basilicum plus ethanol-treated, and cimetidine plus ethanol-treated. The rats received the extract in two different dose concentrations (100 and 200 mg/kg b.w. orally), and cimetidine (100 mg/kg b.w. subcutaneously) for seven successive days. One hour later after the seventh day dose, the rats of the third and fourth groups received a single dose of 70% ethanol (1 ml/rat) orally. Results: The tested two concentrations of the extract showed a dose-dependent preventive index of 54.3% and 84.3% for the small and large dose respectively. It was noticed that the larger dose of the Ocimum basilicum extract showed a gastric mucosal protection nearly similar to that produced by cimetidine. Conclusion: Ocimum basilicum leaves extract was effective in protection of gastric mucosa against ethanol-induced gastric mucosal injury.