The reactions of 4N-phenyl-2-[ 1 -(pyrrol-2-yl)methylidene]-hydrazine carbothioamide (4PL1) and 4N-phenyl-2-[l-(pyrrol-2-yl)ethylidene]-hydrazine carbothioamide (4PL2) with Group 12 metal halides afford complexes of types [M(L)2X2] [M = Zn, L = 4PL1 or 4PL2, X = Cl, Br or I; M = Cd, L = 4PL1, and X = Cl, or L = 4PL2 and X = Cl, Br or I] and [M(L)X2] [M = Cd, L = 4PL1, X = Br or I; M = Hg, L = 4PL1 or 4PL2, X = Cl, Br or I]. The new compounds were characterized by elemental analysis, FAB mass spectrometry, IR spectroscopy, and, in the case of sufficiently soluble compounds, 1H, 13C and, when appropriate, 113Cd or 199Hg NMR spectrometry. The structures of [Hg(4PL1-H)Br] and [Zn(4PL2)2Br2] · 2 EtOH were also studied by single-crystal X-ray diffractometry. In [Hg(4PL1-H)Br] crystallized from the mother liquor of its synthesis, 4PL1 behaves as a monodeprotonated S,N-bidentate ligand. Otherwise, with Hg(II), Zn(II) and Cd(II), 4PL1 and 4PL2 both behave as neutral S-monodentate ligands.