Patients who develop progressive supranuclear palsy with predominant cerebellar ataxia (PSP-C) develop cerebellar ataxia as the initial and principal symptom, may be misdiagnosed as having multiple system atrophy with predominant cerebellar features (MSA-C). Therefore, we investigated the clinical signs and symptoms between PSP-C and MSA-C early in their disease course.We reviewed the medical records of 15 consecutive patients with pathologically proven PSP-C (4) and MSA-C (11). We recorded the presence or absence of clinical features that developed within 2 years of disease onset.The age at onset of PSP-C patients was older than that of MSA-C patients (p = 0.009). The frequencies of falls were higher in PSP-C patients than in MSA-C patients (p = 0.026). Additionally, the development of supranuclear vertical gaze palsy was higher in PSP-C patients than in MSA-C patients (p = 0.011), whereas the frequency of dysautonomia was lower in PSP-C patients than in MSA-C patients (p = 0.035).Older onset, early falls, and supranuclear vertical gaze palsy without dysautonomia may predict the diagnosis of PSP-C in patients with late-onset sporadic cerebellar ataxia.