Malnutrition is frequent in older adults, associated with increased morbidity, mortality, and higher costs. Nursing home residents are especially affected, and evidence on institutional factors associated with malnutrition is limited. We calculated the prevalence of malnutrition in Swiss nursing home residents and investigated which structure and process indicators of nursing homes are associated with residents' malnutrition.; Subanalysis of the Swiss Nursing Homes Human Resources Project 2018, a multicenter, cross-sectional study conducted from 2018 to 2019 in Switzerland.; This study included 76 nursing homes with a total of 5047 residents.; Malnutrition was defined as a loss of bodyweight of ≥5% in the last 30 days or ≥10% in the last 180 days. Binomial generalized estimating equations (GEE) were applied to examine the association between malnutrition and structural (staffing ratio, grade mix, presence of a dietician, malnutrition guideline, support during mealtimes) and process indicators (awareness of malnutrition, food administration process). GEE models were adjusted for institutional (profit status, facility size) and specific resident characteristics.; The prevalence of residents with malnutrition was 5%. A higher percentage of units per nursing home having a guideline on prevention and treatment of malnutrition was significantly associated with more residents with weight loss (OR 2.47, 95% CI 1.31-4.66, P = .005). Not having a dietician in a nursing home was significantly associated with a higher rate of residents with weight loss (OR 1.60, 95% CI 1.09-2.35, P = .016).; Having a dietician as part of a multidisciplinary team in a nursing home is an important step to address the problem of residents' malnutrition. Further research is needed to clarify the role of a guideline on prevention and treatment of malnutrition to improve the quality of care in nursing homes.