Background and aim: Malnutrition is related with serious morbidity and mortality in institutionalized older adults. The aim of this study is to determine the frequency of malnutrition in nursing homes and care homes and to identify the factors associated with malnutrition in these settings. Methods: This multicenter study was conducted in 14 centers of nursing homes/care homes in three different cities. Total number of 1797 residents aged ≥ 65 years was enrolled. Malnutrition screening was made by Mini Nutritional Assessment Short Form (MNA-SF) and full MNA. Statistical analyses were conducted by SPSS 15.0. Results: The median age (min-max) of the study population was 78.0 (65.0-108.0) and 917 (51%) were female. MNA-SF score of the residents was 11 (0-14). According to the MNA-SF 850 (49.3%) residents had normal nutritional status, 654 (38.3%) residents were at malnutrition risk, and 204 (11.9%) had malnutrition. Number of medications, gender, duration of stay in the institution, frequency of family visits, social security status, type of nursing home (government or not), daily life activities (ADL), Geriatric Depression Scale (GDS) and MMSE scores, get up & go test, hypertension, dementia, depression, and Parkinson disease were associated with malnutrition. Regression analyses revealed that get up&go test, GDS, hypertension, and ADL were independently related to malnutrition diagnosed by MNA-SF. Conclusion: This study provides important information on the prevalence and associated factors of malnutrition in a large multicentered setting of nursing homes and care homes. It will direct the screening plans and interventions taken in order to detect, prevent, and manage malnutrition in these settings. © 2013 Elsevier Masson SAS and European Union Geriatric Medicine Society. All rights reserved.