Objective: To assess the relationship between cognitive function, balance, risk of falls and functionality in elderly persons with impaired cognitive function and verify if those with mild cognitive impairment had better balance, functionality and a lower risk of falls than those with dementia. Methods: An analytical cross-sectional study of 33 elderly persons of both genders, aged over 60 years, were evaluated using the Mini Mental State Examination (MMSE), Timed Up and Go (TUG) test, Berg Balance Scale (BBS), Clinical Dementia Rating Scale (CDR) and Barthel Index. Four groups were considered: mild cognitive impairment (MCI; n=9), mild dementia (MID; n=12), moderate dementia (MOD; n=7) and severe dementia (SD; n=5). Data comparison was performed by the Mann Whitney U-test and correlation by Spearman's rank Correlation Coefficient, whit a significance level of ( p<0.05). Results: There was a statistically significant difference in the risk of falls and functionality between the MID and MOD groups, functionality between the MOD and SD groups, and balance, functionality and risk of falls between the MID and SD groups. A moderate correlation between MMSE and BBS (r=0.543; p=0.006) was observed in the MCI group, and a moderate negative correlation between p<0.001) and a strong correlation between MMSE and Barthel (r=0.708; p<0.001) were observed in the dementia group. Conclusion: The deterioration in cognitive function was associated with greater impairment of functionality, balance and an increased risk of falls in elderly persons with dementia, compared to elderly subjects with mild cognitive impairment.