A new acetato bridged 2D coordination polymer with general formula of [Mn(µ-4-ambh)(µ-OAc)(OAc)]n (1) was prepared by the reaction of Mn(OAc)2·4H2O with 4-aminobenzohydrazide (4-ambh) in equimolar ratio. The reaction was done in methanol under reflux condition and the single crystals of 1 were obtained by evaporation of the solvent. The structure of this compound was determined by X-ray analysis, and its spectroscopic properties and thermal stability were also studied. These studies indicated that in this compound, the manganese ions are connected by a mixture of acetate and 4-ambh bridges to form a 2D polymeric network at the bc crystallographic plane. The intermolecular and intramolecular interactions were investigated by Hirshfeld surface analysis. Magnetic studies revealed a dominant antiferromagnetic intermetallic coupling of J = −0.78 cm−1 magnitude. Magnetization measurements suggest a diamagnetic ground state and a small gap of 1.59 cm−1 with the first excited state; while the axial zero-field splitting parameter, D, was calculated at −0.21 cm−1.