Objective The principal objective of this study was to investigate the relationship between insomnia and health-related quality of life (HRQoL) during the early stage of stroke rehabilitation. Methods The subjects were 214 first-time stroke patients admitted to a rehabilitation unit at one of three Korean hospitals. Within 7days after stroke, functions were evaluated using; the Berg Balance Scale, the Modified Barthel Index, the Mini Mental State Examination, the Frontal Assessment Battery, Screening Tests for Aphasia and Neurologic-Communication Disorders, and the National Institute of Health Stroke Scale. Insomnia, depression, anxiety, and HRQoL were investigated at one month after stroke. Insomnia was defined as presence of at least one of the four following; difficulty initiating sleep, difficulty maintaining sleep, early morning awakening, and non-restorative sleep. HRQoL was assessed using the Short Form Health survey SF-8. Depression and anxiety were measured using the Hospital Anxiety Depression Scale. Multivariate linear regression analysis was conducted to examine the association between insomnia and HRQoL. Results The prevalence of insomnia at one month after stroke was 59.5%. Patients with insomnia were more likely to be older and female and to have depression and anxiety. Patients with insomnia had poorer physical and mental HRQoL. By multivariate analyses, physical HRQoL was significantly associated with type of stroke, hypnotic usage, balancing function, and insomnia. Mental HRQoL was significantly associated with balancing function, depression, and insomnia. Conclusion Insomnia was found to be negatively associated with physical and mental HRQoL in stroke patients during the early stage of rehabilitation.