Synthesis and structural characterization of 3d-metal carboxylate complexes with heterocyclic N-donor ligands are of considerable interest due to the potential biological importance of such compounds. In this study the coordination compounds of copper(II) or cobalt(II) valerates or nickel(II) benzoate with nicotinamide (L), [CuL(C4H9COO)2]2, [CuL2(C4H9COO)2], [Co2L4(С4Н9СОО)4(Н2О)], and [NiL2(C6H5COO)2 (Н2О)2] are synthesized, and their crystal structures are determined by the Xray crystallography. The crystals of [CuL(C4H9COO)2]2 consist of centrosymmetric binuclear complex molecules, have a Chinese lantern structure and the Cu coordination polyhedron is a tetragonal pyramid. The Cu...Cu’ distance in the dimer is 2.621(1) Ǻ. The complexes of the composition M:L = 1:2 are six-coordinate. In [CuL2(C4H9COO)2] copper(II) atom has a square bipyramidal coordination. In [NiL2(C6H5COO)2(Н2О)2] the nickel atom as well as the cobalt atom in binuclear complex [Co2L4(С4Н9СОО)4(Н2О)] has octahedral coordination. In all cases the nicotinamide ligand is bound to the metal atom via the nitrogen atom of the pyridine ring, whereas the carboxylate ligands are coordinated by different patterns. Benzoate anions in [NiL2(C6H5COO)2 (Н2О)2] are monodentate. Valerate anions are bidentate in both copper complexes: bridging in [CuL(C4H9COO)2]2 and chelate in [CuL2(C4H9COO)2]. An unusual feature of [Co2L4(С4Н9СОО)4(Н2О)] is the presence of both monodentate and bidentate-bridging valerate anions. The coordination modes of water molecules in [Co2L4(С4Н9СОО)4(Н2О)] and [NiL2(C6H5COO)2(Н2О)2] are also different: in the latter complex both Н2О molecules are monodentate, whereas in the former complex the Н2О molecule bridges two cobalt atoms. Various hydrogen bonds and π-π stacking interactions between planar parallel pyridine fragments play a significant role in the stabilization of structures.