42 Patients with intracranial meningiomas that recceived more than 50 percent of their blood supply from the external carotid artery underwent embolization before surgery. The interval between embolization and the tumor consistency at the time of surgery were recorded. The interval between embolization and surgery was divided into periods such as 6 days, 7-9 days, 10 days and an average tumor consitency score was obtainned in segments. The patients were assigned to two groups, group 1 underwent surgery on a specified day after embolization, group 2 underwent surgery at a later. The authors compared tumor consistency, blood loss, length of hospitalization, surgical resection time, simpson grade at surgery, and complication rate in both groups. Results. on the polynomial regression curve, the greatest tumor softening occurred 7-9 days after embolization. When the postembolization interval exceedad 10 days occured. Compared with group 1 patients, groups 2 patients did not have an increased blood loss, a longer hospitalization, or a higher complication rate. In group 2 the surgical procedure required less time and the simpson grades were lower. Conclusion. in meningiomas that receive more than 50 percent of their blood supply from external carotid artery, the optimal interval betwee embolization and surgery is 7-9 days. This interval allows the greatest degree of tumor softening, which markes it possible to remove the tumor more safely and easily.