Older adults are at increased risk for malnutrition. The aim was to investigate the prevalence of and risk factors for poor nutritional status in oldest-old Chinese. Community-living Chinese aged 90 and over were included in the study. Nutritional status was evaluated by using the Mini Nutritional Assessment short-form (MNA-SF). Demographic and socioeconomic status, health status, cognitive, behavioral, and lifestyle factors were collected via structured questionnaires during face-to-face interviews. 632 individuals (424 F, 208 M, 94 ± 3 y) were included. We found that 36 (5.7%) participants were classified as being malnourished (MNA-SF < 7), 445 (70.4%) were classified as being at risk for malnutrition (8 ≤ MNA-SF ≤ 11), and 151 (23.9%) were considered as well-nourished (MNA-SF ≥ 12). Ordinal logistic regression showed that significant risk factors for poor nutritional status included older age, poor cognitive function, gastrointestinal (GI) system disease, poor self-rated health, and lower serum albumin level. The findings suggest that the majority of the Chinese oldest-old were at risk for malnutrition. Nutritional assessment should be incorporated into regular geriatric screening among community-living oldest-old in China. Interventions targeting those at risk for malnutrition should be developed to improve health outcomes among this vulnerable population.