The reaction of 2-methyl-1,3-benzothiazole (mebta) with mercuryII chloride in methanol in a 1:1 molar ratio resulted in the formation of single crystals of the title compound, [HgCl2(C8H7NS)]n. The molecules exist as continuous chlorine-bridged chains in which Hg atoms lie in distorted trigonal bipyramidal environments. The equatorial positions are occupied by an N atom from the ligand [2.236 (8) A] and two Cl atoms [2.428 (3) and 2.459 (3) A]. The two axial Hg-Cl contacts to two neighbouring molecules [2.874 (3) and 2.964 (3) A] are significantly shorter than the sum of the respective van der Waals radii, and form close to linear Cl-Hg-Cl sequences [177.80 (7) degrees ].