The aim of this study is to measure serum levels of neurotropic factor (NF) in patients with dementia. Brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), and neurotrophin-3 (NT-3) were determined in Alzheimer's dementia patients without medication (AD; n: 22), Alzheimer's dementia patients receiving cholinesterase inhibitor (CEI) treatment (AD + CEI; n: 32) and vascular dementia patients receiving CEI treatment (VaD + CEI; n: 27) and the age-matched control group (n: 20). NGF levels were detected to be significantly higher in the control group than in AD group (P < 0.001). BDNF and NT-3 levels in AD group were not significantly different from control group's levels. NGF levels in AD + CEI group were significantly higher than in AD group (P < 0.05). There was also no significant difference in serum neurotrophic factor levels between AD + CEI and VaD + CEI group. A positive correlation between BDNF and Mini Mental State Examination (MMSE) scores (r: 0.422, P < 0.01) in AD group and a negative correlation between BDNF and MMSE scores in the AD + CEI group (r: -0.357, P < 0.005) were obtained. In conclusion, our results suggest that while serum NGF levels are associated with the presence of dementia, serum BDNF levels may be associated with the severity of Alzheimer's dementia. However, future studies are required to determine the importance of NFs.