Introduction <p>Continuous deep sedation (CDS) provides palliative relief for intractable suffering, especially in the context of cancer. This procedure is recognized to create a specific experiential context for both professionals implementing it and relatives supporting the patient. The aim of the current study was to explore and compare the perceptions and experiences concerning CDS.</p> Methods <p>The APSY-SED study is a multicenter, prospective, and longitudinal study using a mixed-methods design. We present here the qualitative results derived from a lexicometric analysis of interviews conducted with relatives and healthcare professionals at T1 (when CDS is initiated).</p> Results <p>The study included 27 relatives and 22 healthcare professionals. Relatives stressed the finality of time, experiencing sedation with ambivalence: both as a relief for the patient and a source of emotional burden for themselves. They highlighted the importance of respecting patient autonomy and wishes, with strong emphasis on communication and trust in healthcare professionals. Meanwhile, professionals focused on patient care, balancing ethical and legal considerations while upholding patient autonomy. They noted practical and procedural strains around decision-making and underscored the essential role of family communication throughout the sedation process.</p> Discussion <p>These findings underscore the complexity of CDS, revealing the nuanced interplay between relatives’ ambivalence and healthcare professionals’ ethical concerns. Communication clearly emerges as a pivotal element in reconciling these perspectives, particularly around patient autonomy, family involvement, and shared decision-making. Clear legal and ethical guidelines can reduce professionals’ moral distress, and structured education programs for relatives may improve their experience of sedation care.</p>