Parkinson's disease (PD) is the most common neurodegenerative disease after Alzheimer's disease. PD causes degenerative changes in the cerebellum. It is known that the cerebellum does not have a symmetrical anatomy and some pathological disorders may cause asymmetric changes in the cerebellum. In this study, our aim is evaluate whether or not cases with PD show age and gender dependent cerebellar changes and cerebellar asymmetry comparing with healthy subjects. We also aimed to depict the probable cortical thickness differences in cases with PD by using a stereological technique. The study evaluated the volumetric assesment of each cortical cerebellar hemisphere and total cerebellum by applying a stereological technique on magnetic resonance images. The age and gender-matched study was composed of 47 adult cases with PD and 47 healthy subjets as control. In the PD group, right and left cerebellar hemisphere volume, total cerebellum volume, and cortical thickness of the right and left cerebellar hemispheres were significantly lower than the control group (p<0.01). Although there was significant cerebellar atrophy and asymmetry in PD cases with age between 40-71, the study showed no statistically significant cerebellar asymmetry in cases over 70 years of age. However, no significant difference was detected depending on gender. Our findings suggest that in PD, cerebellum’s cortical thickness and volume decreases. The decrease in the volume and cortical thickness of the cerebellum increases with age, regardless of gender, compared to healthy individuals. However, this difference begins to close with age.