Objectives. The aim of this study was, firstly, to determine the number of institutionalizations in homes for the elderly and nursing homes and, secondly, to learn about regional differences in the placement procedure and the pre-existing problems and diseases. Methods. Data were recorded during 1994 by the 143 GPs of the network of sentinel practices, which is representative of Belgian GPs. All placements of adult patients in homes for the elderly and nursing homes were registered. Results. During 1994, Belgian sentinel GPs placed 297 patients in a nursing home or a home for the elderly. Most of them were women and patients who lived alone. At the time of institutionalization, motor function impairment and dementia were the most common diseases. The institutionalizations were motivated mostly by a need for assistance with daily living activities and nursing assistance. An interim hospitalization was necessary in 60% of all institutionalizations. Two-thirds of all patients were on a waiting list. The average length of these waiting lists was shorter in the southern (Walloon) region than in the northern (Flemish) region. Home care services were consulted in 16% of all institutionalizations. In the southern region, home care services were consulted more often than in the northern region. Conclusions. Motor function impairment and dementia were the most common pre-existing impairments. Placements were often hampered by long waiting lists and interim hospitalization. In the southern region, waiting lists were shorter and home care services consulted more often. Some placements could be avoided or delayed by a better organization and promotion of the possibilities of professional home care services.