Since the attempt to evidence structural brain damage in Parkinson's disease (PD) by conventional magnetic resonance imaging (MRI) is usually disappointing, we have investigated whether the magnetization transfer ratio (MTR) can reflect changes in grey and white matter of PD patients. MTR was quantified in 44 regions of interest (ROIs) in both grey and white matter of 11 non-demented PD patients, ranging from 2 to 4 on the Hoehn and Yahr Scale, and eight age-matched healthy subjects. MTR differences between patients and controls were found in the supratentorial white matter and in the brainstem. In particular, lower MTR values were found in the paraventricular white matter of PD patients (p<0.05) while no differences were observed in corpus callosum, frontal, parietal, occipital lobes or centrum semiovalis. Lower MTR values were found in substantia nigra (p<0.001), red nucleus (p<0.05) and pons (p<0.05) of the patient group. No differences were discovered in basal ganglia and thalamus. These findings suggest that MTR measurements in the paraventricular white matter and brainstem may help to recognize a marker for probable PD.