A systematic review of the international literature concerning the organisation of the Geriatric Day Hospital (GDH) was performed. From 1987 till now, few papers were found describing the activity and the effectiveness of the GDH. All the studies comparing specific geriatric approaches to regular medicine demonstrate the efficiency of geriatric care, particularly the geriatric assessment. So, with a degree of evidence 1a, a better outcome is found for patients undergoing a geriatric assessment and intervention, compared to patients having no geriatric assessment at all. However, there is no evidence of benefit for the geriatric day hospital compared to patients treated in a geriatric ward or other location of geriatric care. Moreover, there is no clear consensus on the settings and activities of a geriatric day hospital. Terms as day unit, day hospital, day care, are used interchangeably and are not always covering the same activity. The same remark can be made on the exact composition of the geriatric multidisciplinary team and its role. However nurses and paramedical workers are always mentioned as all performing geriatric assessment. The diagnostic activities on the GDH are seldom described and studied. More information is available on rehabilitation activity, often developed in specific patient populations such as stroke patients, dementia patients, cardiac patients or patients with other chronic diseases. In this selected patient populations positive effects on outcome are shown in the GDH (level of evidence 1a). Another problem is the heterogeneity of the population. For scientific reason the GDH should focus on organising care for specific medical problems. Diseases as dementia, stroke, cardiac insufficiency, could be good models to investigate the efficiency of geriatric assessment and interventions within the setting of a GDH.