Considering the limited information available, the aim of the study was to examine the prevalence and characteristics of inpatients with dementia in Belgian general hospitals. All admissions of inpatients aged at least 40 years with or without dementia were retrieved from the nationwide administrative hospital discharges database for the period 2010-2014. Admissions of inpatients aged 40 years or more with dementia have increased to reach 83,017 out of 1,285,593 admissions (6.46%) in general hospitals in 2014, mostly admitted through the emergency department (79.7%) and for another reason than dementia (85.9%). These patients stayed longer [19.2 days, standard deviation (sd) = 23.6, median = 13] than the average length of stay of patients of the same age (7.9 days, sd = 14.1, median = 17). Considering patients aged 75 years or more falling into the 20 most common pathology groups (of patients with dementia), the group with dementia spent 5 days more than the group without dementia. Patients admitted from home spent more time in hospital when they were discharged to a residential care facility than when they returned home (27.2 days versus 15.8 days). The in-hospital mortality was high in the first days of admission. The growing prevalence of patients with dementia in inpatient setting puts a high pressure on the hospital capacity planning and geriatric expertise. Moreover, as patients with dementia should be kept outside hospitals when possible for safety and quality matters, long-term organizational investments are required inside hospital and residential care settings as well as in community care.