This cross-sectional study aimed to assess the association of risk of cognitive impairment with level of serum uric acid (SUA) among very old people, specifically in a cohort of 694 unrelated Chinese aged 90-108 years. Cognitive function was measured using the 30-item Mini-Mental State Examination (MMSE) and SUA level was determined by the uricase-peroxidase method. Cognitive impairment was defined as a score below 18 on the Folstein MMSE. Men had significantly higher cognitive function scores than did women: 17.6+/-5.6 vs. 14.0+/-5.2 (P<0.05). In the total sample, the prevalence of cognitive impairment was 71.6%, with the rates being 50.9% and 81.6% for males and females, respectively (P<0.000). Men had significantly higher SUA levels than women: 354.1+/-85.7 vs. 303.8+/-81.7mmol/L (P=0.000). Binary logistic regression analysis indicated an inverse correlation between the risk of cognitive impairment and SUA (OR=0.996) in men. In conclusion, in male nonagenarians and centenarians, the higher level of SUA is related to the lower risk of cognitive impairment.