The scarcely known chemistry of silver(I) halides with a series of heterocyclic thiones in acetonitrile (or methanol–acetonitrile) is described. Silver(I) chloride with a series of imidazolidine-2-thiones [C 3 H 5 NS(N–R)] in the presence of one equivalent of PPh 3 with respect to the thione ligand has yielded chloro-bridged dinuclear complexes, [Ag 2 (μ-Cl) 2 (κ 1 -S-C 3 H 5 NS(N–R)) 2 (PPh 3 ) 2 ] (1, R = H; 2, R = Me; 3, R = Et), and in the presence of two equivalents of PPh 3 , it has yielded mononuclear complexes, [Ag(κ 1 -Cl)(κ 1 -S-C 3 H 5 NS(N–R))(PPh 3 ) 2 ] (4, R = Me; 5, R = Et). The n-propyl-imidazolidine-2-thione with silver(I) chloride formed only a mononuclear complex, [Ag(κ 1 -Cl)(κ 1 -S-C 3 H 5 NS(N–Pr n ))(PPh 3 ) 2 ] (6), in the presence of one or two equivalents of PPh 3 . In contrast, silver(I) bromide with C 3 H 5 NS(N–R) in the presence of one or two equivalents of PPh 3 with respect to the thione ligand has yielded bromide-bridged dinuclear complexes, [Ag 2 (μ-Br) 2 (κ 1 -S-C 3 H 5 NS(N–R)) 2 (PPh 3 ) 2 ] (7, R = Me; 8, R = Et; 9, R = Pr n ). The related thio-ligands, namely, 1-methyl-imidazoline-2-thione and thiazolidine-2-thione with silver(I) bromide in the presence of one or two equivalents of PPh 3 have formed bromide bridged dimeric [Ag 2 (μ-Br) 2 (κ 1 -S-C 3 H 3 NS(N–Me)) 2 (PPh 3 ) 2 ] (10) or mononuclear Ag(κ 1 -Br)(κ 1 -S-C 3 H 5 NS 2 )(PPh 3 ) 2 ] (11) complexes respectively. The 2,4-dithiouracil (C 4 H 4 N 2 S 2 ) with silver(I) chloride/bromide and PPh 3 has yielded hetero-bridged dinuclear complexes, [Ag 2 (μ-S,S-C 4 H 3 N 2 S 2 )(μ-X)(PPh 3 ) 4 ] (X = Cl, 12; Br, 13) involving rupture of Ag–X bonds directly with a thio-ligand, a rare case of such rupture in metal-heterocyclic thione chemistry.