Quality assurance has been started in palliative care units since 1999, using a documentation project based on yearly documentation periods. The project was developed by a working party of palliative care specialists in cooperation with the German Cancer Society and the German Association for Palliative Medicine. The aim was a concise but meaningful standard documentation, able to describe the special therapeutic situation of palliative care patients and the interdisciplinary and multi-professional care they receive. In this paper, data of 4693 in-patient treatment periods relating to structural, procedural and outcome quality of palliative care units are presented from the beginning of the core documentation in 1999 through 2001. In 2002, data from palliative care units were compared with those from oncologic and geriatric wards, as well as hospices. Palliative care units show constant traits since the beginning of the core documentation in 1999, in spite of the rising number of participants. At the same time, there are distinct differences among the groups of participants due to the scope of their therapeutic setting. These relate to structure quality in the functional status of the patients (ECOG), which is worst in hospices (> palliative care units > geriatric wards > oncologic wards); to process quality in intensified pain treatment concerning incidence and intensity of pain, which is most frequent and severe in palliative care units (> hospices > geriatric > oncologic wards); and outcome quality in the rate of discharge home, which is highest in oncologic wards (> geriatric > palliative care units > hospices). Quality assurance in palliative care is difficult due to complex indicators, which should be assessed in a standardised documentation. The core documentation was established as a quality assurance programme for palliative care patients. The results of the previous evaluations have enabled the development of a standard documentation. The continuous application of such a standard documentation will prove the quality improvement and development of the participating units.