A growing family of coordination polymers based on the [Mn6(μ4-O)2]10+ structural core mainly consists of 1D polymers with different geometries of chains, for example, linear chains, zigzag chains or wavy chains [1, 2]. Polymers of higher dimensionality are still rare. Here we report the synthesis and crystal structure of a ladder-like polymer {[Mn6O2(O2CCHMe2)10(pyz)1.5(H2O)] • 0.5(H2O)}n (1), where pyz = pyrazine. Compound crystallizes in triclinic space group P-1. The {Mn6} unit has a typical structural motif found in other hexanuclear Mn clusters and coordination polymers based on them. All Mn atoms in 1 are in a distorted octahedral geometry. Charge considerations and bond parameters indicate that the {Mn6} cluster is mixed-valent and contains four MnII and two MnIII ions. The peripheral ligation is completed by ten bridging isobutyrate ligands, two crystallographically non-equivalent exobidentate pyrazine ligands and one water molecule. One of the pyrazine molecules binds two Mn atoms of adjacent {Mn6} clusters related by translation b (Mn...Mn distance is 7.415(1) Å), that leads to the organization of linear chains. Another pyrazine molecule connects neighboring {Mn6} clusters related through the center of symmetry, and forms a bridge between two chains. The corresponding Mn…Mn distance is 7.480(1) Å. As a result, ladder-like chains consist of almost square cells and run along [010] direction (Fig. 1). Figure 1. Ladder-like chain in 1. H atoms are omitted. Figure 2. Fragment of the layer formed by hydrogen bonding (dotted lines) in 1. The chains interact through hydrogen bonds involving the terminal H2O molecule, lattice water molecule and two Ocarb atoms of two neighboring {Mn6} clusters. Thus, chains form hydrogen bonded polymeric layer (Fig. 2). The layers are held together by van der Waals interactions.