OBJECTIVES: To evaluate the prevalence of malnutrition and its impact on mortality, functional decline and cognitive impairment among elder residents in long-term care settings. DESIGNS: A prospective cohort study. SETTINGS: Two veteran homes in Taiwan. PARTICIPANTS: A total of 1,248 male residents aged equal or more than 65 years. MEASUREMENTS: Charlson’s comorbidity index (CCI), Minimum data set (MDS), resident assessment protocols (RAP), Activity of daily living-Hierarchy scale, Cognitive Performance Scale, MDS Social engagement scale. RESULTS: The mean age of participants is 83.1 ± 5.1 years, and the prevalence of malnutrition was 6.1%. Inadequate dietary content (57.9%) and unintentional weight loss (31.6%) account for the majority of malnutrition identified by MDS tool. Higher 18-month mortality rate (25% vs. 14.2%), higher baseline CCI (median 1 vs. 0), and higher baseline sum of RAP triggers (median 8.5 vs. 5) were noted among residents with malnutrition. Furthermore, malnutrition was shown predictive for functional decline (OR: 3.096, 95% CI: 1.715-5.587) and potential cognitive improvement (OR: 2.469, 95% CI: 1.188-5.128) among survivors after adjustment for age, body mass index and CCI. CONCLUSION: Malnutrition among elder men residing in veteran homes was associated with multimoridities and higher care complexity, and was predictive for mortality and functional decline.