Abstract INTRODUCTION Preoperative prediction of blood supply in meningiomas is important to avoid unexpected intraoperative bleeding. Herein, we investigated the relationship between the location of meningioma and the dominant side of feeding arteries. METHOD: Between January 2018 and December 2020, a total of 101 consecutive patients underwent craniotomy for meningioma at our hospital. Among them, 43 cases in which the lesions were clearly localized on the right or left sides received preoperative angiography including bilateral common or external carotid artery (ECA) imaging. A region of interest (ROI) was set at the most stained area in (X) meningioma and (Y) main trunk of the ECA. In each affected side (AS) and healthy side (HS), the ratio of ROI (X) value to ROI (Y) value; tumor / vessel ratio (TVR = 0 ~ 1) was calculated. Multivariate analysis was performed to compare TVR between AS and HS, and to analyze factors associated with TVR, such as site of origin (convexity, skull base and relating falx), age, gender, WHO grading, and tumor diameter. RESULTS TVR was significantly higher in AS (0.60; 0.41 - 0.91) than HS (0.47; 0.39 - 0.99) (p=0.0003). HS was superior to AS in 10 cases, all of which were falx (6 of 9 cases) or parasagittal (4 of 10 cases) meningioma. 53% of falx and parasagittal meningiomas showed HS predominant TVR. Concerning factors associated with the TVR of HS predominance, falx origin was extracted as an independent factor (p< 0.0001). DISCUSSION The vessels crossing in the falx, which consist with particular anatomical structure, fusing the meningeal layers in each side of dura mater would contribute to this finding. CONCLUSION Falx and parasagittal meningiomas should consider the predominant influx of tumor feeding vessels from HS.