PURPOSE: Rural older adults are more likely to be malnourished than urban older adults, particularly those living in lower-middle-income countries like Vietnam. Therefore, this study aimed to address the prevalence of malnutrition and its association with frailty and health-related quality of life in older rural Vietnamese adults. PARTICIPANTS AND METHODS: This cross-sectional study was conducted on community-dwelling older adults (aged ≥ 60 years) living in a rural province in Vietnam. Nutritional status was determined using the Mini Nutritional Assessment Short Form (MNA-SF), and frailty was evaluated using the FRAIL scale. The 36-Item Short Form Survey (SF-36) was used to evaluate health-related quality of life. RESULTS: Among the 627 participants, 46 (7.3%) were malnourished (MNA-SF score <8), and 315 (50.2%) were at risk of malnutrition (MNA-SF score: 8-11). Individuals with malnutrition had significantly higher rates of impairments in instrumental activities of daily living and activities of daily living than those without malnutrition (47.8% vs 27.4% and 26.1% vs 8.7%, respectively). The prevalence of frailty was 13.5%. Risk of malnutrition and malnutrition were associated with high risks of frailty, with odds ratios of 2.14 (95% confidence interval [CI]: 1.16-3.93) and 4.78 (1.86-12.32), respectively. Furthermore, the MNA-SF score was positively correlated with eight domains of the health-related quality of life among rural older adults. CONCLUSION: The prevalence rates of malnutrition, risk of malnutrition, and frailty were high among older adults in Vietnam. A strong association was observed between nutritional status and frailty. Therefore, this study reinforces the importance of screening for malnutrition and risk of malnutrition among older rural individuals. Further studies should explore whether early nutritional intervention reduces the risk of frailty among older adults and increase their health-related quality of life in the Vietnamese population.