The syntheses and crystal structures of a family of silver cyanide complexes of thiourea and substituted thioureas are reported. The sulfur ligands include thiourea (tu), 1-methyl-2-thiourea (mtu), 1,3-dimethyl-2-thiourea (dmtu), 1,1,3,3-tetramethyl-2-thiourea (tmtu), and 2-imidazolidinethione (N,N-ethylenethiourea, etu). Synthesis was effected by dissolving AgCN in an aqueous Solution of ligand. Two different complexes were obtained by the reaction of AgCN with tu. Complex la: (AgCN)(tu), monoclinic, P2(1)/c, a = 9.3851 (6) Angstrom, 6 = 8.2782 (5) Angstrom, c = 7.1178 (5) Angstrom, beta = 94.591 (1)degrees, and Z = 4. Complex 1b: (AgCN)(tu)(2), Viclinic. P (1) over bar, a = 7.9485 (14) Angstrom, b = 9.431 (2) Angstrom,c = 12.771 (2) Angstrom, alpha = 85.695 (3)degrees, beta = 81.210 (4)degrees, gamma = 77.987 (2)degrees, and Z = 4. Complex 2: (AgCN)(mtu), triclinic, P (1) over bar, a = 4.113 (2) Angstrom, b = 9.472 (4) Angstrom, c = 9.679 (4) Angstrom, alpha = 113.918 (5)degrees, beta = 98.188 (6)degrees, gamma = 97.725 (6)degrees, and Z = 2. Complex 3 (AgCN)(2)(dmtu)(2), monoclinic, P2(1)/m, a = 7.1482 (7) Angstrom, b = 14.776 (2) Angstrom, c = 7.3366 (7) Angstrom, beta = 92.418 (2)degrees, and Z = 2. Complex 4: (AgCN)(tmtu), orthorhombic, P2(1)2(1)2(1), a = 8 821(6) Angstrom, b = 10.209 (2) Angstrom, c = 10.362 (2) Angstrom, and Z = 4. Complex 5: (AgCN)(2)(etu)(2), triclinic, P1, a = 6.8001 (2) Angstrom, b = 8.6154 (1) Angstrom, c = 13.4747 (3) Angstrom, alpha = 71.720 (1)degrees, beta = 79.906 (1)degrees, gamma = 75.885 (2)degrees, and Z = 2. All of the structures involve either one- or two-dimensional polymeric arrays held together by bridging S and CN groups. There is, however, no similarity between any two of the arrays. Four of the five ligands used also form similar complexes with CuCN. For one ligand, tmtu, the structures are isomorphous. For the other three, not only are the structures not isomorphous, the m/n ratio in (MCN)(m)L-n when M is Ag is different from that when M is Cu.