Reaction of pyridine-2,4,6-tricarboxylic acid (ptcH₃) with Co(NO₃)2.6H₂O in presence of 4,4′-bipyridine (4,4′-bpy) in water at room temperature results in the formation of [Co₂(ptcH)₂(4,4′-bpy) (H₂O)4]·2H₂O, (1). The solid-state structure reveals that the compound is a dimeric Co(II) complex assembled to a 3D architecture via an intricate intra- and inter-molecular hydrogen-bonding interactions involving water molecules and carboxylate oxygens of the ligand ptcH^2-. Crystal data: monoclinic, spacegroup P2₁/c, a = 11·441(5) å,b = 20·212(2) å,c = 7·020(5) å, Β = 103·77(5)°,V= 1576-7(1) å³,Z = 2,R1 = 00363,wR2 = 0·0856,S = 1·000.