BACKGROUND: Taurine has been proven to play a significant role in cardiovascular and cerebrovascular diseases, but its relationship with moyamoya disease (MMD) remains unclear. This study aims to investigate the association between serum taurine levels and long-term adverse cerebrovascular events in patients with MMD after revascularization. METHODS: This study involved 352 patients with MMD, from whom comprehensive clinical data and blood samples were collected. Serum taurine levels were measured using liquid chromatography-tandem mass spectrometry, and the relationship between serum taurine concentration and various blood indices was evaluated. Cerebrovascular adverse events included transient ischemic attack, ischemic stroke, and hemorrhagic stroke. Taurine, analyzed as a continuous variable, was found to predict a cut-off for postoperative cerebrovascular adverse events in MMD patients at 842.52 μmol/L. The impact of serum taurine levels on the risk of cerebrovascular events was analyzed using Kaplan-Meier (KM) curves, and univariate and multivariate Cox regression analyses were performed to identify predictive factors for postoperative prognosis. RESULTS: Grouping MMD patients by serum taurine levels revealed that higher taurine levels were significantly associated with a lower proportion of hemorrhagic MMD (p = 0.044). Compared with ischemic MMD, patients with hemorrhagic MMD had lower taurine concentrations (p = 0.005). KM curves showed that the incidence of postoperative cerebrovascular adverse events in the high taurine group was significantly lower than in the low taurine group (p = 0.026). Univariate Cox regression analysis indicated that higher taurine concentrations significantly reduced the risk of postoperative cerebrovascular adverse events (Hazard Ratio [HR] = 0.334, 95 % Confidence Interval [CI] = 0.121-0.923, p = 0.035). Furthermore, the multivariate Cox regression model confirmed that taurine level is an independent predictor of long-term adverse cerebrovascular events, with the high concentration group showing a significantly reduced risk. CONCLUSIONS: Low serum taurine levels are associated with a higher risk of long-term adverse cerebrovascular events following MMD revascularization. This suggests the significant potential of serum taurine as a prognostic biomarker for postoperative outcomes. CLINICAL TRIAL REGISTRY NUMBER: URL: https://www.chictr.org.cn/. Unique identifier: ChiCTR2200061889.