Genetic studies have shown that progressive supranuclear palsy (PSP) is associated with inheritance of a specific genotype (H1/H1) in the tau gene. The authors investigated whether the H1/H1 genotype or A0/A0 genotype independently or in conjunction with selected environmental risk factors influences the age at onset, severity, or survival in patients with PSP. Our findings suggest that tau genotyping does not predict the prognosis of PSP.