Argyrophilic grain disease (AgD) is a relatively newly described neurodegenerative disease with late-onset dementia. Morphologically it is characterized by the presence of abundant spindle-shaped argyrophilic grains (ArG) in neuronal processes and coiled bodies in oligodendrocytes. ArG consist of abnormally hyperphosphorylated form of tau protein. AgD is a substrate of at least 5% of all dementia cases with increasing incidence in the old age. Here we report the cases of a 91-year-old woman and an 83-year-old man clinically diagnosed with dementia. Neuropathological, histochemical and immunohistochemical examination of the brain tissue show the changes to be compatible with a definite diagnosis of AgD. This is the first description of two cases of AgD in the Czech Republic.