Quality of palliative care is of interest to everyone receiving or delivering it. Quality indicators are defined as measurable aspects of care referring to structure, process, or outcome and are mostly measured on individual level but interpreted aggregated, e.g. service level. Quality indicator scores can be used to evaluate which aspects of the care are going well and which are not going so well and have room for improvement. Because of the need of a comprehensive quality indicator set reflecting the multidisciplinary and multifaceted character of palliative care, this dissertation presents a 3-step development process, resulting in a minimal indicator set and 3 optional thematic modules that can be used to monitor and improve the quality of palliative care within the specialized palliative care services in Flanders, Belgium. In a first step the quality indicator set was developed by means of a systematic literature review and an expert panel. Second, the comprehensive quality indicator set was tested for feasibility and usefulness in 9 specialized palliative care services by using a mixed-methods design. Overall the caregivers found the indicator set and measurement procedure feasible and useful. Based on this testing, the set and measurement procedure were fine-tuned and an expert panel was organized to select a minimal indicator set for quick and efficient quality monitoring. Last, barriers and facilitators were identified for implementation of the quality indicators into palliative care services in Flanders. Although the quality indicator set is ready to be used by the specialized palliative care services to internally monitor and improve the quality of care, further research is necessary to validate the indicator set for large populations and to measure its effect on patient and family outcomes.