The syntheses and crystal structures of the first cyanide, sulfur mixed ligand copper(I) complexes are reported. The first complex of the family was discovered when (CuCN)(3)(C6H12N4)(2) (1) (C6H12N4 = hexamethylenetetramine) was treated with aqueous thiourea. The sulfur ligands include thourea (tu), 1,3-dimethyl-2-thiourea (dmtu), 1,3-diethyl-2-thiourea (detu), 1,1,3,3-tetramethyl-2-thiourea (tmtu), and 2-imidazolidinethione (N,N’-ethylenthiourea, etu). Synthesis was effected by adding the ligand to a solution of CuCN in aqueous sodium thiosulfate. Complex 2, (CuCN)(2)(tu)(3)(H2O), crystallizes in the triclinic space group <(P)over bar 1> with unit cell dimensions a = 7.696(5) Angstrom, b = 9.346(2) Angstrom, c = 10.772(2) Angstrom, alpha = 106.53(2)degrees, beta = 91.11(4)degrees, gamma = 98.42(3)degrees, and Z = 2. Complex 3, (CuCN)(3)-(dmtu)(2), crystallizes in the monoclinic space group Cc with unit cell dimensions a = 10.082(3) Angstrom, b = 14.984(5) Angstrom, c = 11.413(3) Angstrom, beta = 104.50(2)degrees, and Z = 4. Complex 4, (CuCN)(2)(detu)(H2O), crystallizes in the monoclinic space group P2(1)/n with unit cell dimensions a = 7.969(5) Angstrom, b = 11.559(4) Angstrom, c = 13.736(5) Angstrom, beta = 100.48(4)degrees, and Z = 4. Complex 5, (CuCN)(tmtu) (polymorph a), crystallizes in the orthorhombic space group P2(1)2(1)2(1) with unit cell dimensions a = 8.653(1) Angstrom, b = 14.202(4) Angstrom c = 16.03(1) Angstrom, alpha = 101.68(5)degrees, beta = 107.08(6)degrees gamma = 70.07(2)degrees, and Z = 8. The difference between the polymorphs is that 5 has a zig-zag chain with a repeat unit of two while 6 has a 4-fold helix. Complex 7, (CuCN)(2)(etu), crystallizes in the monoclinic space group P2(1) with unit cell dimensions a = 3.994(2) Angstrom, b = 13.886(3) Angstrom, c = 7.556(1) Angstrom, beta = 97.07(2)degrees, and Z = 2.