The structure of pyridine-2,6-dicarboxylic acid, C(7)H(5)NO(4), has been determined at 0.71 A resolution. The molecule is located on a site with mirror symmetry. A one-dimensional supramolecular structure is stabilized in the solid state through a strong symmetric double hydrogen bond, with H* * *O distances of 1.86 (3) A and O-H* * *O angles of 167 (3) and 171 (5) degrees. This arrangement is similar but not identical to that reported for the isoelectronic isophthalic acid (benzene-1,3-dicarboxylic acid).