Objective <p>To investigate if papaverine improves anastomotic stenosis, promotes microcirculation, and enhances the prognosis of patients with moyamoya disease (MMD).</p> Methods <p>This study enrolled 120 patients with MMD, 60 individuals in the experimental group receiving intraoperative and postoperative treatment with papaverine, and the control group who did not receive papaverine, respectively. We performed transcranial Doppler (TCD), computed tomography perfusion (CTP), and digital subtraction angiography (DSA) before and within 3 days postoperatively to assess the effectiveness of papaverine. TCD measurements included the internal diameter and blood flow velocity of all patients’ superficial temporal, internal carotid, and vertebral arteries. CTP was used to evaluate perfusion in various brain regions, including the frontal, temporal, parietal, and occipital lobes. DSA was used to assess the collateral vessel proliferation in patients diagnosed with MMD. Patient prognosis was evaluated using the Modified Rankin Scale (mRS) score, Random Forest analysis, and monitoring for potential complications.</p> Results <p>Postoperative examination of the parietal and temporal lobes using CTP revealed that the experimental group exhibited shorter time-to-peak, shorter mean transit time, and a higher cerebral blood volume than the control group. Postoperatively, we observed a more significant increase in collateral circulation in the experimental group due to postoperative collateral grading. mRS scores in both groups were statistically different. However, no statistical difference was observed between both groups regarding complications.</p> Conclusions <p>These findings suggest that adding papaverine to revascularisation procedures in patients with MMD promotes anastomotic patency and enhances collateral circulation proliferation, ultimately leading to improved prognosis.</p>