Background <p>Palliative sedation (PS) is a therapeutic measure used in end-of-life care to alleviate the suffering caused by refractory symptoms. The objectives of our study were to determine the frequency of PS in a specialized inpatient acute palliative care unit (APCU), describe the characteristics of patients who received PS, compare patients who required PS with those who did not, and compare patients who received a single medication for PS with those who received multiple medications.</p> Methods <p>This was a retrospective study of 444 patients with cancer who died in a specialized inpatient APCU of a tertiary public hospital.</p> Results <p>A total of 167 patients received PS (38%). The most frequent indication was delirium (64%). The mean duration of PS was 49&#xa0;h. Patients who received PS were significantly younger (<i>p</i> = 0.001), had higher anxiety (<i>p</i> = 0.024), had longer hospital admissions (<i>p</i> = 0.001), were more likely to have a spouse as their primary caregiver (<i>p</i> = 0.003), were more aware of their prognosis (<i>p</i> = 0.024), and had more advance directives (<i>p</i> = 0,001) than those who did not receive PS. Forty-six patients (28%) required two or three drugs for PS. They had a longer PS (<i>p</i> = 0.002) and received more parental hydration (<i>p</i> = 0.015) than did those who received one drug. Patients receiving midazolam as first-line treatment were less likely to receive a second drug (<i>p</i> = 0.003).</p> Conclusions <p>A total of 38% of patients with cancer receiving specialized palliative care required PS before death. Patients who received PS were younger, had a longer hospital stay, were more likely to have their spouse be their primary caregiver, were better informed and had more advance directives. 28% of sedated patients required more than one drug, which was associated with a longer PS, the maintenance of parental hydration during PS and the initiation of PS with levomepromazine instead of midazolam.</p>