Objective: This study retrospectively examined the practice of chlorpromazine (CPZ) administration for sleep disturbance in a palliative care unit, with particular attention to concomitant use of midazolam (MDZ). Methods: A total of 126 patients were reviewed. Among them, 98 patients who continued CPZ for three days or longer were evaluated for changes in nighttime sleep status using a sleep score and for daytime consciousness level. Results: MDZ was used concomitantly in 99 patients (78.5%). Adverse events related to CPZ were observed in 12 patients (9.5%), mainly oversedation and extrapyramidal symptoms, while no severe circulatory or respiratory suppression was noted. Among the 98 patients who received CPZ continuously for three days or longer, sleep scores showed an improving trend; however, some patients experienced decreased daytime alertness, and the possibility that adverse events were underestimated cannot be excluded. Conclusion: This study was a retrospective, single-center analysis based on medical records and therefore has limitations related to the subjectivity of assessment tools and clinical judgment. Further prospective studies using standardized evaluation scales are required to establish the efficacy and safety of CPZ for sleep disturbance.