Depression, anxiety and posttraumatic stress disorder (PTSD) are common complications of cerebrovascular diseases. However, they were seldom explored in Moyamoya Disease (MMD) survivors. In this study, we measured the prevalence of depression, anxiety and PTSD in MMD survivors. We evaluated the association of mental disorders with neurological disability and cognitive impairment, and further find out the independent protective and risk factors of neurological disability and cognitive impairment. In MMD survivors, the prevalence of these three mental disorders is high, 46.7% for depression, 50% for anxiety and 47.5% for PTSD. Anxiety and PTSD were significantly associated with more severe neurological disability (p = 0.039 and < 0.001); depression and anxiety were significantly associated with greater cognitive deficiency (p = 0.004 and 0.002). We further found PTSD was the only risk factor associated with neurological disability, and the corresponding odds ratio (OR) and 95% confidence interval (CI) was 81.74 (9.91-674.17); depression and anxiety were risk factors associated with cognitive impairment, and the corresponding OR and 95%CI were 2.73 (1.10-6.81) and 3.37 (1.29-8.78). Therefore, these three mental disorders were associated with more severe neurological disability and greater cognitive deficiency in MMD survivors.