Progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD) have overlapping clinical features that can make clinical distinction between these two entities difficult. The present study compared the frequency of photophobia, visual hallucinations, and REM sleep behavior disorder (RBD) in patients clinically diagnosed with PSP to those clinically suspected to have CBD. Photophobia occurred in all 10 (100%) PSP patients vs 2 (18%) patients with clinically suspected CBD (p=0.0002). Visual hallucinations and RBD occurred in patients with PSP and CBD but were rare occurrences (5% for each symptom). The presence of photophobia is significantly more frequent in clinically diagnosed PSP than CBD and can be used as a feature in differentiating between the two diseases in clinical practice. Visual hallucinations and RBD occur infrequently in PSP and CBD and are not useful symptoms in clinical differentiation.