Objective: Patients with incurable cancer should receive general palliative care according to their needs, as provided through collaboration between hospital departments, municipalities, and general practices and as outlined in national guidelines. However, the implementation of general palliative care in Denmark has been inadequate. This study aimed to investigate the healthcare professionals' (HCPs') perceptions on barriers to and facilitators of the implementation of the Danish National Guideline (NG) for general palliative care. Methods: This descriptive, qualitative study was guided by the Consolidated Framework for Implementation Research (CFIR). Qualitative focus group and individual interviews were conducted with 23 HCPs. The interview guide, coding, analysis, and reporting of findings were developed within the CFIR framework. Results: The main barriers to implementing NG were as follows: lack of knowledge about the NG, lack of an implementation plan, and insufficient communication and collaboration across sectors. Important facilitators were as follows: HCP motivation to meet palliative care needs, HCPs with special functions taking responsibility for incorporating NG into local guidelines, and the role of district nurses specialised in palliative care as opinion leaders providing security and continuity for the HCPs working in palliative care. Conclusions: To address the needs of patients with incurable cancer, greater efforts are required on implementing general palliative care. Although HCPs in our setting were motivated to improve NG implementation, financial resources and strategies are necessary to ensure sufficient knowledge uptake and accommodate identified barriers in order to translate the NG into practice.