Objective To investigate the impact of arachnoid cut open during indirect revascularization on the clinical effect of revascularization in children with ischemic-type moyamoya disease.Methods A retrospective analysis was performed for the clinical data of 21 children (28 sides) with ischemic-type moyamoya disease who underwent indirect revascularization from August 2010 to November 2015; 12 children (18 sides) were enrolled in opened arachnoid group and 9 (10 sides) were enrolled in unopened arachnoid group. Magnetic resonance imaging and digital subtraction angiography (DSA) were performed at 12 months after surgery to evaluate the clinical effect of revascularization in the two groups, with reference to clinical symptoms.Results Both groups had formation of collateral circulation and improvement in perfusion-weighted imaging, and at 12 months after surgery, the opened arachnoid group had a significantly higher good and general rate than the unopened arachnoid group (94.44% vs 60%, P<0.05). There was no significant difference in the improvement of clinical symptoms after surgery between the two groups, and the opened arachnoid group had a higher excellent and good rate than the unopened arachnoid group (88.89% vs 60%, P<0.05). There were no significant differences in complications between the two groups.Conclusions Cutting the arachnoid open during surgery may improve the effect of indirect revascularization in children with ischemic-type moyamoya disease.