Aim: The purpose of this study was to compare the cognitive/affective and Activities of Daily Living (ADL) functions of Parkinson’s Disease (PD) and Progressive Supranuclear Palsy (PSP). Methods: We retrospectively recruited 324 PD patients, 109 PSP patients, and 111 control subjects, and investigated their cognitive/affective and ADL functions, especially in PD patients when compared with PSP patients. Results: Cognitive functional scores (MMSE, HDS-R, FAB, and MoCA) of total PD and PSP were lower than the control. In particular, recent and working memory, initiation, executive functions, and attention of PSP were significantly lower than total PD. Affective functional scores (geriatric depression scale, Apathy Score: AS, and Abe’s BPSD score) of total PD and PSP were worse than the control, and AS of PSP was significantly worse than total PD. Within PD, cognitive/affective, and ADL functions were expressed in an H-Y stage-dependent manner. Conclusion: Our results demonstrate that the PSP cognitive functions and AS were significantly worse than the PD. Moreover, the cognitive/affective and ADL functions of PD were similar to, or worse, than PSP in severe H-Y stages of PD, suggesting greater dysfunctions of both motor symptoms and cognitive/affective functions in an advanced stage of PD than PSP.