The reaction of Cd 2(thf) 5(BF 4) 4 with two equiv. of TlHB(3-Bu t pz) 3 (pz=pyrazolyl ring) produces the intermediate {HB(3-Bu t pz 3Cd}BF 4 that reacts with potassium thiocyanate to yield HB(3-Bu t pz) 3Cd(NCS) ( 1). The solid state structure shows that the sterically demanding 3- tert-butyl groups enforce the formation of a tetrahedral, monomeric complex, the first four-coordinate cadmium(II)-thiocyanate complex to be structurally characterized. The decomposition of this compound produced (Bu t Hpz) 2Cd(NCS) 2 n ( 2) as shown by X-ray crystallography. It was not possible to form a lead(II) complex analogous to 1, but using less sterically demanding ligands allowed the preparation of {HB(3,5-Me 2pz) 3Pb(μ-NCS)} 2 ( 3), and {HB(pz) 3Pb(μ-NCS)} n ( 4). The former has a dimeric structure with both μ-NCS- S, N and μ-NCS- S, S bridging SCN − ligands and the latter has a infinite 2-D layered array in which three nonequiv. {HB(pz) 3Pb} + groups sandwich a layer of SCN − ligands. Using neutral 2,6-pyridyl-diimine ligands (pydim) having bulky 2,6-dimethylphenyl substituents, parallel complexes of both metals were prepared. The cadmium complex, (pydim)Cd (NCS) 2BF 4 2 ( 5) is dimeric with normal μ-NCS- S, N bridging groups. The structure of the lead(II) analog, (pydim)Pb(NCS)BF 4 ( 6) is monomeric with an N-bound, isothiocyanate ligand and a four-coordinate lead(II). The structure of 6 is very different from 5, presumably because of the stereoactive lone pair on lead(II). A series of mono-thiocyanate complexes of cadmium(II) and lead(II) supported by coordination to bulky ligands, such as HB(3-Bu t pz) 3Cd(NCS) (pz=pyrazolyl), {HB(3,5-Me 2pz) 3Pb(μ-NCS)} 2, (pydim)Cd (NCS) 2BF 4 2 (pydim=2,6-bis(2,6-dimethylphenylimino)pyridine) and (pydim)Pb(NCS)BF 4 have been prepared and structurally characterized. Both HB(3-Bu t pz) 3Cd(NCS) and (pydim)Pb(NCS)BF 4 are unusual examples of four-coordinate cadmium–lead(II)-thiocyanate complexes.