Palliative sedation (PS) is a medical intervention aimed at alleviating refractory suffering in patients with advanced disease through the controlled reduction of consciousness. Although it is an essential practice in PS, its application continues to generate conceptual, ethical and procedural controversies among healthcare professionals. The aim of this review was to systematically explore and map the global scientific evidence on the knowledge, attitudes and practices of healthcare professionals regarding PS. A scoping review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews and Joanna Briggs Institute guidelines. The search was conducted in PubMed/MEDLINE, Web of Science, Scopus, BVS, LILACS and the Cochrane Library, covering publications from 2015 to June 2025. Of 2,204 records identified, 61 studies met the inclusion criteria. The results revealed significant gaps in knowledge, particularly regarding indications, pharmacology and the distinction between PSE and euthanasia. Attitudes were generally positive, although influenced by cultural, religious and ethical factors. Clinical practices showed considerable variability: midazolam was the most commonly used drug, while opioids were misused in several contexts. The lack of standardised protocols and interdisciplinary consultation contributed to heterogeneity and increased moral distress among healthcare teams. It is concluded that a disconnect between theory and clinical practice persists. Strengthening ethical and clinical training, developing context-specific guidelines and promoting interdisciplinary decision-making are key actions to ensure safe, equitable and compassionate end-of-life care.