The reaction of [AuCl₄]^- with Cy₂P(O)C(S)N(H)Me in the presence of thiodiglycol affords the air-stable adduct Au[Cy₂P(O)C(S)N(H)Me] Cl which features a linear gold atom geometry defined by a chloride atom and a sulfur atom derived from a monodentate thioformamide ligand. The pale-green crystals are monoclinic, space group P2₁, with unit cell dimensions a 18.507(4), b 12.204(2), c 18.513(6) Ǻ, β 117.69(2)°, Z 8; the structure was refined to final R 0.042, 4106 reflections being used.