BACKGROUND CONTEXT: Sleep disturbance is highly prevalent in patients with spinal cord injury and is one of the most important clinical issues affecting their quality of life. However, it has not been properly measured or treated in patients with cervical myelopathy (CM), although most typical or atypical symptoms of CM are known to be risk factors for sleep disturbance. In addition, previous studies identified that the presence of sleep disturbance is unintentionally missed under the current evaluation process for degenerative spinal disease without direct investigation using validated tools for sleep. Therefore, studies about sleep disturbances in patients with CM are essential. PURPOSE: The purpose of this study was to investigate the prevalence of sleep disturbance in patients with CM using validated tools and to understand its mechanism by identifying high-risk patients. STUDY DESIGN/SETTING: Cross-sectional study. PATIENT SAMPLE: Consecutive patients diagnosed with CM. OUTCOME MEASURES: Pittsburgh sleep quality index. METHODS: This study was performed on patients diagnosed with CM. Sleep disturbance was determined using the Pittsburgh sleep quality index. Variables associated with sleep disturbance including demographics, lifestyle, medical history, and radiologic parameters were investigated. Independent risk factors related to sleep disturbance were identified using multivariate logistic regression analysis. RESULTS: A total of 203 patients with CM were included in our study. Among them, 126 patients (62.1%) were men, and the mean age was 63.0 years. Despite male predominance, sleep disturbance was identified in 71.4% of patients (145 of 203). Multivariate analysis identified a worse depression scale score, a lower modified Japanese Orthopedic Association score, chronic shoulder joint pain, smaller spinal cord area, and decreased cervical range of motion as independent risk factors for sleep disturbance. CONCLUSIONS: In patients with CM, sleep disturbance was associated with a more severe type of myelopathy. Further studies including polysomnography and measurement of melatonin will be helpful to identify the mechanisms of the sleep disturbance in patients with CM and to improve their quality of life and clinical outcomes.