A new highly anisotropic coordination heterobimetallic polymer [Mn-III(Schiff-base)](3)[Re-IV(CN)(7)] was synthesized and characterized structurally and magnetically. The single crystal X-ray analysis has revealed that this is the first framework among the complexes composed of homoleptic cyanometallate and Mn-III complex of the tetradentate Schiff base ligand. A formation of 3D assembly is possible due to both the pentagonal bipyrimidal geometry of the cyanome-tallate unit and suitable size of constituents: [Re(CN)(7)](3-) and [Mn-III(acacen)](+), where acacen = N,N'-ethylenebis-(acetylacetoneiminato). The powder and crystal magnetic studies show that the compound undergoes an antiferromagnetic ordering of a complicated character below Neeltemperature of 13 K, and exhibits a metamagnetic behavior and strong magnetic anisotropy similar to those observed in related 3D Mn-II-[Mo(CN)(7)](4-) systems. Unusual magnetic properties of [Mn-III(acacen)](3)[Re-IV(CN)(7)] (1) originate from an interplay of Re-Mn anisotropic spin coupling and ZFS effect of Mn-III ions with a noncollinear orientation of the local magnetic axes in the cyano-bridged 3D network. A theoretical model of anisotropic spin coupling between orbitally degenerate [Re-IV(CN)(7)](3-) complexes and Mn-III ions is developed, and specific microscopic mechanisms of highly anisotropic spin coupling in Re-IV-CN-Mn-III linkages in complex 1 are analyzed in detail.