Zn (II)-tetra(3-hydroxyphenyl)porphyrin (C44H28N4O4Zn) was obtained as solvate (1:2) by recrystallization of the commercially available metalloporphyrin derivative from dimethylsulphoxide (DMSO). The crystals are monoclinic, space group C2/c, with a = 1883.9(4) pm, b = 1200.9(2) pm, c = 2084.6(5) pm and β = 117.45(2)°. They consist of five-coordinated square-pyramidal metalloporphyrin units, involving one DMSO ligand at the axial position. These units are cross-linked in the lattice by an extensive network of hydrogen bonds. The second molecule of the DMSO approaches the other side of the porphyrin core. It is not linked to the metal center, but takes part in H-bonding interactions with adjacent porphyrin molecules. The 1:2 porphyrin-DMSO clusters are orientationally disordered in the crystal lattice.