Differential diagnosis of idiopathic Parkinson's Disease is still very difficult. Even in movement disorders centers 25% of patients with clinical diagnosis of Parkinson's disease is misdiagnosed with other neurodegenerative disorders. Clinical symptoms of so called atypical parkinsonian disorders may emerge late in the course of the disease, not at the same time and good or moderate response to levodopa at early stages may be a source of misdiagnosis. Most difficult to differentiate seems to be Progressive supranuclear palsy (PSP), corticobasal degeneration (CBD) and multiple system atrophy (MSA). Authors present in selected cases usefulness of neuroimaging with rCBF SPECT and MRI in clinical diagnosis of these disorders. For PSP typical (although not pathognomonic) is decrease of metabolism and flow in frontal lobes (hypofrontalism), and in CBD asymmetrical, contralateral to the side of dominating symptoms cerebral (frontal, parietal, temporal and within striatum) atrophy. In MSA more useful (but not seen in all cases) is MRI examination with hyperintensities in putamen, pons and cerebellum or cerebellar atrophy. Due to low sensitivity of clinical criteria other tests (EMG of anal sphincter or clonidine test) with specially neuroimaging examination may be helpful in establishing of the diagnosis.