Background:In dementia, functional status depends on multiple factors in addition to cognition. Nutritional status is apotentially modifiable factor related to homeostasis and proper functioning of body systems and may contribute to cognitiveand functional decline.Objective:This paper aims to analyze the association of malnutrition with the course of cognitive and functional decline inpeople living with dementia.Methods:This is an analysis of a longitudinal cohort study, the Dementia Study of Western Norway. Data of 202 patientsdiagnosed with mild dementia were analyzed; Alzheimer’s disease (AD) (n= 103), Lewy body dementia (LBD) (n= 74),and other dementias (OD) (n= 25). Cognition was assessed with the Mini-Mental State Examination and functional declinethrough the activities of daily living included in the Rapid Disability Rating Scale. The Global Leadership Initiative onMalnutrition Index was used to determine nutritional status. Associations of nutritional status with cognitive and functionaldecline were evaluated through adjusted linear mixed models. Results:At baseline, the prevalence of general malnutrition was 28.7%; 17.3% were classified as moderate malnutrition and11.38% as severe malnutrition (there were no significant differences between AD and LBD). Malnutrition at diagnosis andover follow-up was a significant predictor of functional-decline, but not of cognitive decline.Conclusion:According to our results malnutrition was associated with faster functional loss but, not cognitive decline inolder adults with dementia. A more comprehensive dementia approach including nutritional assessments could improveprognosis.