In the title compound, [Pt(C17H19N4)Cl], the Pt(II) cation is C,C',C''-chelated by the 1,1'-(5-methyl-1,3-phenyl-ene)bis-(3,5-dimethyl-1H-imidazolyl-idene) anion and coordinated by a Cl(-) anion in a distorted square-planar coordination geometry. π-π stacking is observed between nearly parallel imidazole and benzene rings of adjacent mol-ecules, the centroid-centroid distance being 3.802 (4) Å.