INTRODUCTION Malnutrition is an under-recognised and under-treated problem often affecting older adults. AIM The aim of this study was to evaluate the prevalence of and factors associated with malnutrition and frailty among older adults at early admission to residential aged care. METHODS A cross-sectional study was undertaken among eligible older adults within the first week of admission to residential aged care. Participants were assessed for malnutrition risk using the Mini Nutritional Assessment Short Form, frailty using the Fried phenotype criterion, muscle strength using a grip strength dynamometer and gait speed using a 2.4-m walk test. A Cox regression analysis was conducted to identify factors associated with malnutrition risk and frailty status. RESULTS Of 174 participants (mean age 85.5 years, 61% women), two-thirds (66%) were admitted to residential aged care from the community. Most (93%) were either malnourished (48%) or at risk of malnutrition (45%). A total of 76% of participants were frail and 24% were pre-frail. Forty-three percent were both malnourished and frail. Low risk of malnutrition was associated with increases in muscle strength [0.96 (0.93-0.99)], gait speed [0.27 (0.10-0.73)] and pre-frailty status [0.32 (0.12-0.83)]. DISCUSSION This study provides preliminary evidence for high prevalence of malnutrition and frailty at admission to residential aged care. Almost all participants were malnourished or at nutrition risk. Findings highlight the need for strategies to prevent, detect and treat malnutrition in community health care and support nutrition screening at admission to residential aged care.