Purpose: To evaluate cerebral hemodynamic disturbance in patients with symptomatic unilateral middle cerebral artery (MCA) high-grade stenosis or occlusion using dynamic susceptibility contrast perfusion magnetic resonance imaging (DSC-pMRI). Material and Methods: DSC-pMRI was performed in 28 patients with symptomatic unilateral MCA high-grade stenosis or occlusion. Hemodynamic parameters including relative cerebral blood flow (rCBF), relative cerebral blood volume (rCBV), relative mean transit time (rMTT), and time to peak (TTP) were calculated and compared between the stenosed or occluded side and contralateral side. Seven of the 28 patients underwent surgery or interventional therapy, and hemodynamic changes between pre- and post-therapy were investigated. Results: Prolonged rMTT and TTP were found in the stenosed or occluded MCA territories in all 28 patients. Significant differences were found in rCBV (P < 0.05), rMTT (P < 0.001), and TTP (P < 0.001) between the stenosed or occluded side and the contralateral side. However, no significant difference was observed in rCBF (P > 0.05). In the seven patients with surgical or interventional therapy, the values of rMTT and TTP significantly decreased after surgery or interventional therapy (P < 0.001). Conclusion: DSC-pMRI may be a useful tool for evaluating and monitoring cerebral hemodynamic disturbance in patients with symptomatic unilateral MCA high-grade stenosis or occlusion.