In the title salt, C(5)H(6)ClN(2) (+)·C(7)H(5)O(3) (-), the carboxyl-ate mean plane of the 4-hydroxy-benzoate anion is twisted by 7.16 (9)° from the attached ring. In the crystal structure, the cations and anions are linked via O-H⋯O and N-H⋯O hydrogen bonds, as well as C-H⋯O contacts, forming a three-dimensional network. In addition, weak π-π inter-actions involving the benzene and pyridinium rings, with centroid-to-centroid distances of 3.8941 (9) Å, are observed.
* Title and MeSH Headings from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.