Hydrogen bonding in crystalline 3,5-pyridine dicarboxylic acid has been studied by H-2, N-14, and O-17 nuclear quadrupole resonance. The H-2 and O-17 data show the presence of two distinct hydrogen bonds, a "normal" O-H center dot center dot center dot O bond and a short, strong N center dot center dot center dot H center dot center dot center dot O bond, with significantly different NQR parameters. In the latter, the temperature variation of the N-14 nuclear quadrupole resonance (NQR) parameters is related to the phonon-driven proton transfer in the N center dot center dot center dot H center dot center dot center dot O hydrogen bond. The temperature dependence of the N center dot center dot center dot H and H center dot center dot center dot O distances in the N center dot center dot center dot H center dot center dot center dot O hydrogen bond is extracted from the N-14 NQR data.