Reactions of pyridine-2,6-dicarboxylic acid (H₂PDA) with cobalt(II) acetate resulted in two cobalt(II) complexes, [Co(HPDA)₂]·2H₂O·0.5CH₃OH (1) and [Co₂(PDA)₂(H₂O)₅]·2H₂O(2), which were characterized by single-crystal X-ray diffraction, IR and electronic absorption spectra. For both complexes, every cobalt atom lies in peudo-octahedral coordination geometry, and the whole structures present 3D frameworks linked by π-π stacking interactions and extensive hydrogen bonds. Magnetic studies showed λ = –83.38 cm^-1 for (1) and g = 2.50 and J = –1.38 cm^-1 for (2).