Background: In terminally ill patients with cancer, sleep disturbance makes worse their quality of life. Midazolam has not ever been used for the treatment of sleep disturbance in general wards of our hospital, used in palliative care unit of other hospital, however. Method: This is a retrospective study based on chart review. Twenty-eight patients who were treated with midazolam for sleep disturbance included in this study. We designed evaluation methods to strictly follow the actual chart descriptions. Efficacy was rated as good, fair, or poor. Safety was defined by the presence or absence of respiratory depression and hypotension. Results: The median administration periods and initial doses were 6 days (range, 1-151) and 5.0 mg/night (1.8-20.0), respectively. Fourteen patients showed good sleep a night after midazolam infusion, four and nine patients showed fair and poor sleep, respectively. No patient demonstrated a respiratory rate of less than 8/min and systolic blood pressure of <60 mmHg at any point during and after midazolam infusion. Conclusion: Intravenous midazolam appeared to be safe for sleep disturbance of terminally ill patients with cancer in general wards. A future improvement administration methods are necessary to treat for sleep disturbance more effectively as well as PCU.