Frontotemporal lobar degeneration (FTLD) is a clinically, pathologically, and genetically heterogeneous group of disorders that affect the frontal and temporal lobes of the brain. FTLD classification distinguishes three main neuropathological groups: FTLD-tau, FTLD-TDP, and FTLD-FUS. As a four-repeat tauopathy, argyrophilic grain disease (AGD) is included in the FTLD-tau group. AGD may also appear in association with other neuropathological disorders. We describe the demographic, clinical, neuropathological, and genetic characteristics of a series of FTLD cases presenting with AGD. For this purpose, a clinico-pathological study of 71 autopsy-confirmed FTLD cases from different tissue banks was performed. AGD was found in 52.1% of FTLD cases. The presence of AGD increased with the increasing age (up to 88.9% in cases older than 80 years; p