We report the histopathological and immunohistochemical findings from the brain of an elderly patient diagnosed with Parkinson's disease (PD). Neuropathological examination revealed moderate neuronal cell loss and astrocytosis in the substantia nigra. Lewy bodies were found in many sites characteristic for PD, including the substantia nigra, locus coeruleus, hypothalamus, substantia innominata, pontine raphe nucleus, and dorsal motor vagal nucleus, cingulate and insular cortices. Furthermore, argyrophilic glial intracytoplasmic inclusions were found predominantly in the ventral pons, cerebellar white matter, precentral and frontal white matter, internal and external capsule, claustrum, and putamen. Inclusions were triangular in shape, and immunopositive for ubiquitin and alpha-synuclein. In view of these histopathological and immunohistochemical findings and patterns of distribution, the inclusions were suggested to be glial cytoplasmic inclusions (GCIs) in multiple system atrophy (MSA). These findings suggested that our case might have experienced two pathological processes; PD and the early stage of MSA (striatonigral degeneration) that had not progressed to striatal involvement. Alternatively a common pathological background including abnormal processing of alpha-synuclein could contribute to widespread accumulation of Lewy bodies and GCIs in a single condition accompanied by nigral degeneration.