Background and objective Idiopathic intracranial hypertension (IIH) is associated with venous sinus stenosis (VSS). While stenting has shown potential as a treatment for VSS in patients diagnosed with IIH, clinical outcomes remain variable. Current predictive markers for treatment success are limited. This study aimed to investigate the predictive value of the Upstream Stasis (US) sign, recently proposed based on our imaging observations, in forecasting treatment success in venous sinus stenting for patients diagnosed with IIH. Methods We retrospectively analyzed data from 102 patients with IIH who underwent venous sinus stenting between May 2016 and August 2024. Patients were categorized based on the presence or absence of the US sign, identified through color-coded cerebral blood flow (CBF) maps. Clinical outcomes were assessed at the 12 month follow-up. Multivariate logistic regression was used to identify independent predictors of favorable outcomes, adjusting for demographic and anatomical factors. Results The US sign was present in 64.7% of patients and was significantly associated with favorable clinical outcomes (sensitivity 74%, specificity 88%, C-statistic 0.81). Multivariate analysis confirmed that both the US sign (OR 31.6, 95% CI 7.15 to 232.2) and intrinsic stenosis (OR 7.68, 95% CI 2.00 to 36.3) were independent predictors of favorable outcome. Subgroup analysis suggested that the US sign provided additional prognostic value beyond morphological classification into intrinsic and extrinsic stenosis. Conclusion Our study suggests that the US sign may serve as a valuable imaging biomarker for predicting the outcomes of stenting in patients with IIH and VSS. Large-scale prospective studies are warranted to validate its clinical utility and broader applicability.