AIMS AND OBJECTIVES: To prospectively investigate and describe the prevalence and incidence of malnutrition among home-living older people, related to demographic and medical factors, self-perceived health and health-related quality of life. Another aim was to find predictors for developing risk of malnutrition. BACKGROUND: Risk factors for malnutrition have previously been identified as diseases, several medications, low functional status, symptoms of depression and inadequate nutrient intake. Most studies are cross-sectionally performed at hospitals or in nursing care settings. DESIGN: A prospective study with a sample of 579 home-living older people, randomly selected from a local national register. Examinations were performed at baseline and yearly follow-ups two to four times. METHOD: Questionnaires validated and tested for reliability, to detect risk of malnutrition (Mini Nutritional Assessment), symptoms of depression (Geriatric Depression Scale-20), cognitive function (Mini Mental State Examination), health-related quality of life (Nottingham Health Profile), well-being (Philadelphia Geriatric Center Multilevel Assessment Instrument) self-perceived health, demographic factors, anthropometry and biochemical examinations. Predictors were searched for through multiple logistic regression analysis with the MNA as dependent factor. RESULTS: The prevalence of risk for malnutrition was 14.5%, according to the MNA. Two risk factors for malnutrition were lower handgrip strength and lower self-perceived health. The incidence of risk for malnutrition at follow-ups was between 7.6% and 16.2%. Predictors for developing malnutrition were higher age, lower self-perceived health and more symptoms of depression. Men with symptoms of depression had a higher risk of developing malnutrition. CONCLUSION: Lower self-perceived health had the highest power to predict risk for malnutrition, with increased number of depression symptoms and higher age as second and third predictors. RELEVANCE TO CLINICAL PRACTICE: A regular and combined assessment using the Mini Nutrition Assessment, Geriatric Depression Scale-20 and self-perceived health as a base for identifying people in need, is one way to prevent the development of malnutrition.