Assemblies of ofloxacin (Hoflo) with Cu(II), in the presence of the organonitrogen ligands, such as 2,2′-bipyridyl (bpy), 4,4′-dimethyl-2,2′-bipyridine (dmbpy), and 8-hydroxyquinoline (hq), under similar conditions, yield a series of three coordination complexes, [Cu(oflo)(bpy)(H2O)](ClO4)(H2O)1.5 (1), [Cu(Hoflo)(dmbpy)(ClO4)](ClO4)(H2O)2 (2), and [Cu(oflo)(hq)](ClO4)(H2O)2 (3). All three complexes have been structurally determined and characterized by physico-chemical and spectroscopic methods. All of the Cu(II) atoms adopt the similar square pyramidal coordination geometries. However, when considering the longer Cu–O contacts in 2, its coordination geometry turns out to be distorted octahedral and a binuclear motif is afforded. The results reveal that, distinct extended network architectures of 1D (for 1) and 2D (for 2 and 3) are further constructed with the aid of weak secondary interactions of H-bonding and aromatic stacking, by introducing various heterocyclic co-ligands. The thermal stabilities of the complexes are described and discussed.