Studies on manganese complexes have attracted considerable interest due to their various properties like biomimetic, catalysis and molecular magnetism. 2,6-Diacetylpyridine is an excellent precursor for synthesizing hydrazone Schiff bases, and its versatile coordination behavior (in neutral, mono- and/or double deprotonated/protonated forms) produce unusual geometries in its metal complexes including those of manganese. Most obtained complexes have pentagonal-bipyramidal geometry with pentadentate coordination of dihydrazone via pyridine nitrogen, two azomethine nitrogens and two carbonyl oxygens (N3O2), while apical positions are occupied by monodentate ligands.  The solvothermal template reaction of MnCl2.4H2O with 2,6-diacetylpiridine, isonicotinic acid hydrazide and Ca(NCS)2.4H2O in ethanol affords a trinuclear complex Mn2CaL2(NCS)2Cl4(H2O)2 (I), where H2L=2,6-diacetylpiridine bis(isonicotinoylhidrazone). This sample is soluble in organic solvent such as chloroform, N,N-dimethylformamide, and less soluble in methanol and ethanol.  Compound I crystallizes in monoclinic centrosymmetric P21/c space group: a=19.739(2), b=8.1633(12), c=17.2494(18) Å, β=112.136(12)°, V= 2574.6(6) Å3. The trinuclear unit resides on inversion center and comprise one Ca(II) and two Mn(II) metal atoms, two hexadentate H2L ligands, two water molecules, two NCS– and four Cl– anions. Each Mn(II) cation adopts an N3O3Cl seven-coordinated pentagonal bipyramidal geometry going from the pentadentate Schiff base ligand in the equatorial plane, while the axial vertices are occupied Cl anion and H2O molecule, both coordinated in a monodentate fashion. The Ca(II) atom is six-coordinated with N4Cl2 octahedral geometry, two nitrogen atoms are from H2L ligands and another two N atoms from NCS anions in equatorial plane, and two Cl anions are in apical positions. The self-association of trinuclear aggregates in I occurs via O–H...N/S and C–H...Cl/S hydrogen bonds generating a 3D supramolecular network.