We describe two extended haplotypes that cover the human tau gene. In a total of similar to 200 unrelated caucasian individuals there is complete disequilibrium between polymorphisms which span the gene (which covers similar to 100 kb of DNA), This suggests that the establishment of the two haplotypes was an ancient event and either that recombination is suppressed in this region, or that recombinant genes are selected against. Furthermore, we shaw that the more common haplotype (H1) is significantly over-represented in patients with progressive supranuclear palsy (PSP), extending earlier reports of an association between an intronic dinucleotide polymorphism and PSP.