The title complex, [NiCl2(CH4N2S)2], has been synthesized from the previously reported (diaminomethylidene)sulfonium chloride–thiourea (3/2) salt [Zouihri (2012b ▶). Acta Cryst. E68, o257]. The NiII ion is coordinated in a distorted tetrahedral geometry by two molecules of thiourea [Ni—S = 2.3079 (7) and 2.3177 (6) Å] and two chloride anions [Ni—Cl = 2.2516 (7) and 2.2726 (7) Å]. The bond angles at the Ni atom lie between 96.69 (2) and 115.40 (3)°, while the dihedral angle between the mean planes of the two thiourea ligands is 6.36 (15)°. The crystal structure is characterized by intra- and intermolecular N—H⋯Cl hydrogen bonds, which lead to the formation of two-dimensional networks lying parallel to the ab plane. The networks are linked via classical N—H⋯Cl and N—H⋯S hydrogen bonds, forming a three-dimensional arrangement.