Purpose : The purpose of this study was to analyze the correlations among bone mineral density(BMD), serum lipid levels, and cognitive function in the elderly with dementia. Methods : We recruited seventy elderly with dementia(men=35, women=35) to participate in the Korean mini mental state examination(K-MMSE). Their T-scores and serum lipid levels were analyzed for correlation analysis. Results : The results of this study showed that there are significant correlations between cognitive function and three factors BMD, low-density lipoprotein cholesterol(LDL-C) level, and total cholesterol(TC) level. The cognitive function scores increased proportionally with BMD but were inversely proportional to LDL-C and TC levels. There were no significant relations among cognitive function, high-density lipoprotein cholesterol(HDL-C) level, and triglyceride(TG) level. Conclusion : These results indicate that there is a direct proportionality between cognitive function and BMD and inverse proportionalities between cognitive function and LDL-C level and between cognitive function and TC level. Therefore, these levels can be indices for preventing and predicting dementia.