OBJECTIVE: To investigate the effect of asiatic acid (AA) on vasospasm in an experimental model of subarachnoid hemorrhage (SAH). STUDY DESIGN: Sixty male Wistar albino rats were divided into 3 groups: Group I=control group (Group Ia: anatomy study group, Group Ib: sham surgery group), Group II=subarachnoid hemorrhage (SAH) group (Group IIa: decapitation 1 hour after SAH, Group IIb: decapitation 72 hours after SAH), Group III=drug administration group (Group IIIa: AA given 1 hour before SAH and decapitation 1 hour after SAH, Group IIIb: AA given 1, 24, and 48 hours after SAH and decapitation after 72 hours). The SAH was created with single bleeding model. The AA was administered 30 mg/kg (single dose for group IIIa, 3dose for group IIIb, intraperitoneally). Basilar artery (BA) lumen area, wall thickness, arterial wall changes, endothelial apoptosis, and DNA damage were evaluated in histopathological sections. RESULTS: The increased average wall thickness after SAH was significantly reduced by AA treatment. In the treatment group, the average lumen area of BA was increased statistically significantly, and pathological changes in the artery wall and endothelial DNA damage and apoptosis were decreased or absent. CONCLUSION: Findings in this study suggest that AA inhibits vasospasm or reduces its severity by its antiinflammatory and antioxidant properties. © Science Printers and Publishers, Inc.